Just got the Weird Tome from the Ghost Librarian, and just for kicks, tried giving it to Khelvaster. (This is in the village, after saving him with AoLS.) Got the following message:

Khelavaster curiously looks at the uncursed weird tome. "Huh? Oh, I have read
that a long time ago. Pretty interesting." Khelavaster drops the
uncursed weird tome.

Haven't seen this documented anywhere. (searched the Guidebook and Forum)