I see no reason to delete it or make it invisible. I'm sure I can remember which book I've read or not
. Sure, as your library grows it will start to be an hassle to scroll through pages and pages of books, even with the 20 books/page option. But that will only be true when my collection surpasses the 500 books mark or something.
That "." trick... Is there something similar, but that would make all read books appear in the last pages? The books are organized alphabetically in general, or per folder?
If I make this directory tree:
1 - Unread
2 - Read
All books in the "1 - Unread" folder would be displayed first?