Yes, you can list multiple books in one listing! This is a great option for when you have all the books in a series, or have multiple books from one author.
Here are some musts when creating multiple-book listings:
Ensure that your listing details (title, photos, and description) include information about all the books in the listing.
Choose an accurate weight for all the books in the listing combined. In addition to being able to select a preset range for the weight, you will also have the option to enter the exact weight in ounces. If you have a scale handy, consider checking the weight of the book as part of your listing process to ensure that the shipping cost on your sale is correct!
Please note that if you do list multiple books together it can only be with a single buying price for the whole lot. You cannot, for example, list prices for individual books within the description of a single listing. Those books should each have their own listing.