Using CSV Import/Export you can update your product information in bulk by exporting products from the Export CSV section and importing the CSV file after making all the required changes. You can update the following details :
1.Material
2. Retail Price
3.Expedited Shipping
4.Price
5.Expedited Days to Deliver
6.Title
CSV feature on our app is only for updating products on the app, it has nothing to do with Shopify and Tophatter Marketplace. If you want to update products on Tophatter, then after importing just upload the products. But make sure that you have disabled the syncing of the product for that particular field which you have updated by CSV or else it will be changed again.