Deleting table's sample items is not removing all the data

There isn’t any reason that this page should be a dynamic page and is probably the reason for getting “mystery” entries. In fact, this page isn’t even connected to a dynamic-dataset and therefore isn’t event properly configured as a dynamic page.

You should redefine this page as a regular page and the table should appear empty when first opening the page. The search function that you have should then properly populate the table.