In the hidden camp in Act 2, if you click on Leah's journal you'll get one journal at a time, the one corresponding to what quest you're on. But if you go to the Inn you can get all the books up to the quest you are on.
Ex: If I'm on quest 3 I get Leah's journal 12, and only 12. Not 10, 11, and 12. But if I go to the Inn I can get Heavy Tomes 1,2, and 3.
So basically I can not go to the Inn at all during Act 2, go there right before I go to Act 3 and get all the books in 1 shot. This doesn't seem to be what is intended judging from how all the other journals and books drop.