You can call a book lover a bibliophile. If you find it impossible to leave a bookstore without buying at least one book, you might be a bibliophile. A bibliophile usually has a huge collection of books and loves nothing more than browsing in a used bookshop or a library. A love of books or a deep knowledge of them makes a person a bibliophile. The earliest use of the word bibliophile was in 1820s France, and it came from the Greek prefix biblio, or "book," and the word philos, or "friend."

Source: Vocabulary