Whether a book is a bow depends on the context.

• Book: In the context of reading material, like a novel or textbook, a book is not a bow.
• Bow: In the context of archery equipment, a book is not a bow.
• Bow: However, "bow" also refers to the act of bending at the waist as a sign of respect or greeting. Merriam-Webster definition of bow
• Book Bow: A "book bow" may refer to decorations made from the pages of a book that resemble bows. Etsy book bow examples

Therefore, unless you are referring to a decoration or the act of bowing, a book is not a bow.