The HTML Table Designer is not supported in the UWA. You would interrogate the table like you would any other web control. Are you running into an issue with interrogating the table? 

I have attached an example of how you can replicate a table using the UseKeys property of the TR control within the HTML table designer. To get the TR underneath the TABLE, you need to edit the os file and actually move the TD controls underneath the TR. If you don't need them under the TABLE, you can interrogate the TR using Select Element and then interrogate each TD. I changed the match rules of the TD to ignore the Row in the match rules so they work on any row.