Hello There,
Thanks for contacting WPML Support. I will try my best to assist you in this matter.
I understand what you're looking for. In order to understand the process of translating the Product tabs created using the WooCommerce Product Tabs(by Barn2) plugin, Please check the steps mentioned in this video: hidden link
If the products mentioned for a particular tab are translated into English, they will automatically be assigned once that specific tab is translated into the English language. If you want, you'll also be able to manually add English products to the English tab.
I hope the video will clear things up for you. Please let me know if you need any further assistance. I will be happy to help.