Here's one way to do it.

Add an extra column to your table, give it a name and variable that to you indicates that it is the column row identifiers.  Give it the CSS Class Name of "labelPlaceholderColumn".

Include this CSS with your form: 

/*hide the labelPlaceholderColumn fields*/
.labelPlaceholderColumn {display : none;} 
/*hide the header for the Label Placeholder Column - be sure to update the q # to match your field*/
#q1 {display : none;} 

Include this Javascript with your form: 

$(document).ready(function() {
  
  //Upon form load, copy the table row labels into the labelPlaceholderColumn fields
  $('.labelPlaceholderColumn input').each(function() { 
    $(this).val($(this).closest('tr').find('td').first().text()); 
  });
  
});

When the form is first loaded, whatever you populated for the row labels will copy into this new column (which will be hidden from view by the CSS).  Then you can include this new value in your report and it should give you the labels you need for your export.