we can make these empty book shelves right? well then we could collect books and stick them on shelves.

As for existing book shelves, they could be clickable, and then would produce one of those nice grey menus with text, similar to a retainer menu, but instead of actions, there would be a list of "books" to "check out" and read. We could even have a new animation similar to the Arcanist animation but without the flashy lights and summons. While a person was in "book" mode, it would be similar to being distracted. The animation could also be similar to the various dances that loop, but the thing that might loop would be page flipping.

They could later add the "while sitting" version.

Lore, and possible "easter eggs" could be found in various pages of some books and book shelves, sort of like the unspoiled nodes with the waterfowl feathers that keep changing positions.