Can I delete the dummy data generated by BYOB?

Yes, you can do so. You can visit Dashboard => Setting => Data Management. Just select the period and click the Clear Now button.

When a customer adds a bundle to cart, our app creates a new variant. The variant is stored in dummy products. For each product, only 100 variants can be stored. That's why our app created new "container" products to store variants. These container products are hidden from the storefront search and search engines. 

When time goes by, either the customers have paid for the variants or they become abandoned. You can clear these variants to tidy up your Product Admin.