Apple books app showing books I didn't purchase in my library

I've bought and downloaded 1 book on the Books app on my iphone. This morning I woke up and found that my library had 33 books! Books I never ordered or downloaded. A lot of them are English classic novels so I assume they're free but at least one of them is not free. It doesn't look like I've been charged for any of them and I don't know how to view my purchase history for books, but it's strange. Does Apple randomly give out and add Books to people's libraries?