Hello,

Additional information tab only shown when you add attributes to the products. If you want to delete the Additional information tab you have to remove all the attributes from the product as in the screenshot: https://jmp.sh/xeQzWmV

The “About Brand” tab only display when you add brand attributes to some product. So if you don’t want to display that tab just remove the brand attributes from the products and not the other attributes. In result “About Brand” tab will not shown.

Best Regards.