"Literacy" was always the most basic tool of necromantic propaganda. If you are not literate you cannot be fed necromancer propaganda. The most steadfast anti-necromancer I knew in my childhood was my maternal grandfather who was illiterate. Necromantic propaganda did not reach him

God dammit I need to get this game don't I?

Can a necromancer raise the Etten to fight for you or do you have to start a crusade against them?

for FUN, you could let someone read it, then set them up in an office as a permanent manager/bookkeeper who never needs to eat.

you could also set up a resurrection chamber where you take newly deceased citizens (or citizens you "deceased" on your own). This chamber would have an adjacent room with some sort of enemy in it, with view blocked by a wall of fortifications and a drawbridge. Necromancer is in the room, you drop the bridge so they see the enemy. They panic, and resurrect the nearest corpse. There's a chance this resurrected corpse is an intelligent undead. Do this 10-20 times and you have a squad of soldiers who never get tired and never have to stop training to sleep or eat.

Necromancers can be lots of fun, or lots of FUN.

I don't think they read the tablet itself, though. From what I've read it has to be in a book. In adventure mode, though, you can totally read the slab!