Hello,
If you add information to product long description https://prnt.sc/23w1xpe it appears in the Description tab https://prnt.sc/23w215x
So, if you want to remove that tab then just clear the long product description. Besides, you had the wrong custom code with the unclosed tags https://prnt.sc/23w2ip5 It caused the issue with the page HTML structure. I removed that and your table looks this way https://prnt.sc/23w2o9z
So, be attentive when you add the custom code to the product description.
Regards