In lords of nal hutta it says that the empire put restrictions on slavery( excluding hutt territory) these restrictions were bad enough for many hutts to sell of there slaving operations to less well informed people before the law was in effect. Now I know the empire used a cap ton of slaves including wookiees so It couldn't be a blanket ban and the legends material I found is conflicting. So what I'm asking is do any of the game books elaborate on slavery in the empire? if not what do you think it is it just a full on ban and the empire is on mass ignoring its own laws for everyone to see ?Do the slavery laws affect only certain species(outlawing or allowing specific species) does it only allow the government o keep slaves, what do you think?

The Empire bans private personal ownership of slaves. However, that doesn't mean that the Empire can't use its prisoners as penal labor, and they're not beyond putting the populations of entire worlds (such as Kashyyyk) into such a state with fairly flimsy excuses. These prisoners can be used for anything from construction to privately boosting the morale of Imperial officers. The Empire can also loan out such penal work crews to certain privileged corporations (SFS, KDY, etc.) but the prisoners technically are not owned by those corporations. Corporations can also hold individuals in indentured servitude, which is very similar to slavery, but not quite the same thing.

The Empire bans private personal ownership of slaves. However, that doesn't mean that the Empire can't use its prisoners as penal labor, and they're not beyond putting the populations of entire worlds (such as Kashyyyk) into such a state with fairly flimsy excuses. These prisoners can be used for anything from construction to privately boosting the morale of Imperial officers. The Empire can also loan out such penal work crews to certain privileged corporations (SFS, KDY, etc.) but the prisoners technically are not owned by those corporations. Corporations can also hold individuals in indentured servitude, which is very similar to slavery, but not quite the same thing.

The Empire bans private personal ownership of slaves, with the exception of droids. But yes you got the point very well. The State may use slaves (they explicitly named many workers on the death star Slaves, that were bought and brought in by Trandoshans (mostly Wokkies) AND Penal labor Prisoners.

I believe Wookiees and some other species were declared to be non-sentient animals by the Empire so they were legally considered pets or labor beasts rather then slaves by the Empire.

It's a big galaxy. So while the global policy of the Empire is "Nope, no slaves!" the application of that policy almost certainly varies from region to region. Some governors crack down hard on that sort of thing, others use the Company Store method and others probably give no F and let people do what they want (as long as they get a cut of the profits and there isn't too much trouble).

The Empire's slavery ban is nominal, and hypocritical. They ban slaving because it looks good to the populace that most supports the Empire, but don't really care about it much beyond that. Instances where they enslave an entire planetary population/species are covered up, dolled up as beneficial or putting down an insurrection, or they try to convince the populace that the more non-human species are little more than animals.

The only instances where the Empire may aggressively pursue instances of slavery is (A) if the slaves are humans (and probably only humans from the Core/Inner Rim), or (B) a particular Customs official makes it their personal agenda (because it's still technically illegal, so they won't get in trouble for it).

The Empire's slavery ban is nominal, and hypocritical. They ban slaving because it looks good to the populace that most supports the Empire, but don't really care about it much beyond that. Instances where they enslave an entire planetary population/species are covered up, dolled up as beneficial or putting down an insurrection, or they try to convince the populace that the more non-human species are little more than animals.

The only instances where the Empire may aggressively pursue instances of slavery is (A) if the slaves are humans (and probably only humans from the Core/Inner Rim), or (B) a particular Customs official makes it their personal agenda (because it's still technically illegal, so they won't get in trouble for it).

You could go all IRL cynical too and say that they oppose slavery because it isn't taxed.