Those are not miniature books in the photo. The top five books represent the complete first edition of Audubon’s Ornithological Biography. Underneath them is "The Birds of America."
Considered a masterpiece of ornithology art, the 3½ -foot-tall books feature hand-colored prints of all the species known to Audubon in early 19th century America. Audubon insisted on the book’s large format — printed on the largest hand-made sheets available at the time — because of his desire to portray the birds in their actual size and natural habitat.This book size is referred to as a "double elephant." See this 2010 post for an explanation of the terminology (and an old photo of one of the books opened).