In the above code if you use: window << Get XML or window << Show Tree Structure you'll figure out it's a splitterbox.
The data table is a unique object in JMP (for good reasons). It's meant to be stand alone in it's own window, b/c of this it doesn't appear support the regular window functions, <<get XML, <<child, << parent, << top parent, ect. The Get Window() function is our savior in this case as it allows us to gain access to the window object holding the data table.
Cheers!