1. The id of tab: It is generated automatically after you add the shortcode Tabs. Basing on this id, we can check in code if there is any error for this section in front end without finding one by one in back end builder. Therefore you do not need to care about it
2. With each tab, you can set each content for that tab. So when you want to remove something, just click on that tab then remove the contained content.
If it is still not your intention, please take the screenshot for the field you are talking about then I will give you the correct answer.
Regards,
Yame