A miniature book is a very small book, sized from .9 inches square to roughly 4 inches square. The majority of these books are from the 18th century, made for portability. One could carry a vast number of books in a small case for when one traveled.
Subjects range from the Bible, encyclopedias, music, stories, rhymes, and accounting records. They are now collectors' items , with prices ranging from a few hundred to many thousands of US dollars.
Some of the oldest books are actually miniature clay tablets from Mesopotamia.