Is there a list somewhere of items revealed in sub-Vaults in Watch Fortress Erioch, there description and year/events at their opening?

I believe that you'll only find them mentioned off-handedly in the various books. A compiled list would be interesting, though.

A list like that would definetely be a helpful tool for working around the vault.

Deathwatch GM Kit

5 pg.

"The Vault reacted to news of the Trellis on Baraban by revealing a trio of archeotech luminators."

6 pg.

"The top slides off a nearby pedestal, and with a hiss of objection from the ancient actuators, three identical archeotech luminators rise into view from within.
The engravings are of clear Imperial craftsmanship, and a soft blue light shines perpetually through the intricate stained glass
chimneys.”

10 pg.

"The light of the archeotech luminators reacts with the strange nature of the devices, making them visible and
tangible for short intervals where the azure light falls. Shining the lamps into the area is obviously the easiest way to find
the Delirium Trellis, but the players might devise their own clever plans for locating the source of the shadow that do not
involve the luminators."

Time isn't usually mentioned but some of the items mentioned offhandedly in books…This is Omega Vault only. There are a plethora of items contained in the vaults of Erioch. The equipment chapter for example…

Core Rulebook pg. 167

The shrouded motives of the Omega Vault revealed this ornate gold chalice the day Watch Captain Mordigael assumed his role as Master of the Vigil. (Blood Angels Relic Chalice of Vision)

Core Rulebook pg. 330

Most secret of all are the terrible devices kept in the outer catacombs of the Omega Vault, the great sealed chamber at the heart of Watch Fortress Erioch. Such weapons include vortex torrent imploder charges, dread canisters of the life-eater virus, and the imprisoned nightmare childe.

Core Rulebook pg. 333

In the past, the vault has provided tomes of archaic lore, strange fragments of alien devices, ancient weapons forged in times long gone, world-slaying virus canisters, enigmatic star charts, and bizarre xenological specimens. On one occasion, its gift was an ancient Astropath held in a stasis field. When
awoken, the Astropath sent one brief astropathic message and spoke two words before expiring from extreme old age, his final duty discharged.

Rites of Battle pg. 249

Has ideas for GMs of what may be contained in the Omega Vault.

Emperor Protects pg. 128

Has an idea for GMs what may be in the final chamber.

First Founding pg. 98

A modification of the tech that created Hellfire Bolt Rounds, the Hellfire Flamer was recovered from the Omega Vault shortly after the first reports of Hive Fleet Dagon reached the Watch Fortress.

The Achilus Assault pg. 33

(These are worded as somewhere between definitely having happened and ideas for a GM) a broken power sword of unknown origin, a bloodstained
back banner of a lost successor Chapter, or a spent bolt casing with a single letter carved into its side. A star chart of the edges of the Hadex Anomaly or the ciphers for a series of Tau sector relays within the Greyhell Front.

Also "Whispers in the Dark." (Worded as definitely having happened.)

Say clues point toward the final chamber holding something massive or an army of smaller things. Leading to speculation there's an actual army in there.

Achilus Assault pg. 63

Upcoming location of the "Mortis Thule" (A Space Hulk.)

Achilus Assault pg. 65

Expands on the Omega Vault sending Battle Brothers to the "Mortis Thule."

Achilus Assault pg. 82 (Actual Date!)
In 779.M41 a ship bearing the Lilium of Charadon’s markings drifted into the Ormasim system. Three Deathwatch Battle-Brothers, veterans of the Kaggeran Pogrom, boarded the derelict to investigate. No sooner had they boarded than the ship’s Warp engines surged to life, carrying the Lilium into the Empyrean. The mysterious return and disappearance of the Lilium coincides with an opening of the Omega Vault. The leaden doors swung wide revealing a single drop of blood hanging in a suspensor fi eld. The blood and the gene-print identifying its origin are currently under seal by order of Watch Commander Mordigael.

Achilus Assault pg. 98 (Adventure seed)

Mephidast’s (Daemon Prince of Nurgle) influence, however, is foretold by the opening of the Omega Vault, revealing cryptic messages of a “black river of plague and decay” unfolding at a specific place and time.

Achilus Assault pg. 108

The Tyranids’ presence on Meskaile was fi rst reported by the Deathwatch, who were there in response to a scrap of information rendered on ancient parchment from the depths of the Omega Vault. Whether it was the Tyranids or
some other threat that the vault intended the Deathwatch to combat was never discovered, for the Kill-team was forced to extract in the face of overwhelming opposition from both the denizens of Meskaile and the newly arrived Tyranids.

Mark of the Xenos pg. 128
An entire data log (basically a journal entry from an unknown source) is presented that is believed to have originated from the Omega Vault.

That's what I could find.

there's also these bits and pieces from the deathwatch timeline.

263.M36

The Lord of Lightning : In response to the opening of a cell in the Omega Vault and the revealing of a broken spear of archaic design and unknown material, a Deathwatch Kill-team undertakes a quest to the Feudal world of Sovereign, which they discover suffers under the grip of a murderous xenos energy-entity which has offered itself as a false messiah to the natives. The spectral creature has grown strong on the life-forces of thousands sacrificed in its name and is worshiped by an army of savage warriors. A single Deathwatch Battle-Brother returns to Erioch with the Thunder Lord’s shattered crystal heart.

656.M40

The Fury of Hell : The Hadex Anomaly comes into being, swallowing the hive world of Verronus. It is believed that the Anomaly emerged due to the bloody rites performed by those dark souls that abided there. Across the Jericho Reach, nascent pyskers burn and daemons stalk the land as a sudden wave of unholy power ripples through the localised area of Warpspace. Those afflicted psykers are either sent irrevocably mad or transfigured into short-lived and murderous demigods who kill thousands and further push those few worlds that remain under civilised control over the brink. On Watch Fortress Erioch, a full third of the Astropathic choir dies, weeping blood. The Omega Vault opens, yielding up a holo-projector that shows only the image of a face mask in the shape of a golden human skull.

715.M41

The Visitation : Two Inquisitors arrive at Watch Fortress Erioch unannounced, their credentials and ciphers for access all in order. One calls herself Camilla Noesis, and the other claims the name Kaleb, but hides his face behind a featureless mask of tarnished silver. They give no explanation of how they learned of the Watch Fortress’s location; they simply say that the time was as it should be. Their arrival coincides with an opening of a chamber within the Omega Vault. Within is found a chronograph dating from the Dark Age of Technology which appears to be meticulously marking a countdown of time, measuring the hours and their divisions with total precision. The Chamber of Vigilance stands in discussion for thirteen days and nights. The two
Inquisitors take all records of their discussions as they leave.