You can find more information about Product Bundles here.
The Product Bundle Component Import/Export allows you to add or remove SKUs from Bundle SKUs in bulk.
Note: In order to update Bundle SKUs, you must first create the Bundle SKUs either via Products > Product Catalog Manager or via Product Import.
Please review the Product Bundle Component Import legend for more details on the columns.
The Product Bundle Component Export allows you to see what SKUs have been assigned to Product Bundles, and the Product Bundle Component Import allows you to update the quantity of an assigned SKU, add new assigned SKUs, or remove SKUs from bundles.