If you would like to remove some products from the list of connected products shown in the API dashboard section Stores, you first need to delete the product via Woocommerce dashboard and then sync products in the API dashboard.
1) Go to Woocommerce dashboard section 'Products'→'All products' and click on the 'Bin' button
2) Then, open the Gelato API Dashboard. Enter section 'Stores' and select your Woocommerce store.
3) Click on 'Sync products' button located on the top right corner of the page. The removed product will no longer be listed after syncing products.