On the left pane you can see the javascript code, the right two panes are empty. Hit F5 to run the script, this will fill the right two panes with data.
The top right pane called Engine shows the variables the code has created in the javascript engine. The bottom pane show the result of the script, this is what will be returned to Excel.
Double click the Acounts node in the bottom pane to zoom in:
Zooming in on the Accoutns table by double-clicking
Variables you see in the Engine and Result pane can be zoomed in by double-clicking them, this can be helpful when dealing wit lots of data.