1.) Go to edit your requirement and click on the text so that you pull up the table settings in the bottom of the Narrative box.
2.) Click on the Set Cell Properties button
3.) Hit Select All and then hit the image next to "Style Builder"
4.) Click on Border
5.) Check the top box "Style Builder_Same for All" for "Border Style", "Border Width" and "Border Color"
6.) Go to Border Style and set the "Top" drop down to the 3rd option under "None".
7.) Set the top option for Border Width to "1".
8.) Set the top Border Color to the color option that you prefer.