Bloodstained: Ritual of the Night

While moving though the Area "Livre Ex Machina" you will stumble upon a Vampire by the name of Orlok Dracule [with a rather familiar Voice for some~]. This fellow will allow you to Check Out Books from his Library that provide Stat Buffs as long as you are Carrying them.

While this Achievement mentions Borrowing 10 Books that is kind of Vague so lets Clarify. The amount you can Borrow at once Expands over time in the Game, and this Achievement Tracks the "Books Borrowed" stat on your Personal Stat Page. You can Simply select, and deselect a book 10 times upon meeting Orlok to Unlock this.