It says make a difficult scholastic lore (military tactics) test. I don't see military tactics anywhere in the core rulebook. It's on page 98.

I googled scholastic lore military tactics and no results came up.

What the hell is it talking about? Does it mean Tactica Imperialis?

Yes, they mean Tactica Imperialis. This is another common error found in the 40k RPG lines.

Military Tactics specializations appear in Deathwatch. Before that, it's just Tactica Imperialis.

Thanks for the replies, I figured as much. Something that could have been fixed in the errata.