Reviews is it's own block on BlockLab, however you can add it to Tabbed Content also.
You will find Product Reviews in Products > Reviews
As you can see, we have a review from a product named 'Product Name Two'.
You can approve and reject reviews, and filter any you do not wish to be displayed on your products.
Clicking on the review will allow you to check the response in detail, as well as approving or rejecting it.
Clicking 'Save & Approve Review' will save the review and display it on said product page.
Rejecting means it will be deleted.
We can now see the review live on the product page.