Hello,

If you are adding the tabs in the single product layout. It will work for all the products. If you want to use the tabs for individual products.

Navigate to Products > Edit Product > In the edit product page check the product settings and click on the tabs settings and create a custom tab for this product and choose the HTML Block for this product.
See screenshot for clarification:
https://ibb.co/z53zhnm

Best Regards.