Books is simply a victory lap for Dear Catastrophe Waitress. This is essentially a concept EP. Each song has something to do with books, including "Wrapped Up in Books," the Dear Catastrophe Waitress single around which this EP is built.
While this isn't Belle and Sebastian's best EP (I'm partial to Dog on Wheels) it does show that they had more than enough good ideas for Dear Catastrophe Waitress. This is just a sign that everything is going right, and as such is a more than welcome addition to the stellar Belle and Sebastian EP catalog.
Baleeted? As a former librarian, it would be wrong to delete this. Also, it's too good to delete.