This is the content tab, where you can turn things like categories, fitment tables, and product attributes on and off.
A few things to note, you will want to leave the MPN added to titles, otherwise BigCommerce wont allow you to load two different products with the same title. The MPN makes each title unique.
You can also chose to load the fitment tables into a second tab, but this needs to be done before loading products, or you need to delete and reload them for the change to take affect.
On the bottom of the tab are all the fields the app synchronizes. You can turn any of these off by deselecting the check box. Say you want to customize your product descritpions, you'll want to deselect that box before making chnages, otherwise our app will update the product and wipe out the changes!