You mean I can make that upper window useful? Yes. Not only that, but, what ever columns you add to the upper window, your copy of Management Studio remembers what you did. The next time you open this Extended Events session in the the Live Data window, the columns you selected will be there. However, your ability to customize Live Data is even easier than that. If you notice, in the upper part of your SSMS window is the Live Data tool bar. Near the end is a button innocuously titled “Choose Columns.” Click on that and a window similar to this will open:
And you can share the results with others.