The Shortcode Element allows you to add a shortcode to a table.
Even though a shortcode is just a text with square brackets, it won’t work on a table if you insert it in the Text Element.
You must drag and drop the ‘Shortcode’ element on the table’s cell, select the shortcode element, and enter your shortcode at the left sidebar.

Make sure to preview the table before saving it. That’s how you use the Shortcode element in a table.
Hope this quick tutorial helped you to understand how to use shortcode in WP Table Builder. If you have any questions regarding this, feel free to ask via comment.