If you have product reviews enabled for your store, this page will allow you to create a new product review by pressing the "Add" button. If the "Add" button is grayed out, product reviews have been disabled. You can turn this feature on by going to Settings -> Product Reviews, and checkmark "All Product Reviews".
Also, if a review has been added to this product, it will show the review, the score, and the date it was created. It will also give you the option to edit or delete it.