I wonder if the "Speak with Dead" Spell is the only spell we will get from this book. It would make sense to give players two opportunities to learn this spell, in case every party member misses the perception check for the crypt button to find the amulet.

I always give the book to Astarion (Gale already gets the other magical items, loot distribution has to be fair), because I think he has a legitimate interest in it.

When he wonders if it could maybe bring the dead back to life, I thought of the True Ressurection spell.

Could this work for Astarion? He mentions that he became a vampire spawn nearly 200 years ago, so the time limit could be met. I know he is undead, not dead, but he did die nearly 200 years ago. Would we have to kill him first for this spell to work?

I am by no means a rules expert, but could this be one way to free Astarion from Cazador's control, so he does not need to keep the tadpole to achieve this?

(By the way, I love the cutscene when Astarion is reading the book- or arguing with it. And we also have a prove that he does not intent to kill us, it's clearly meant as a joke when he adds "Maybe Shadowheart" (or Gale etc.) 😉)