Looking at the Runtime Revolution site now, I see that Media 3.5 is supposed to contain Data Grid capability and, indeed, I am able to download a demonstration stack that explains the use of Data Grids in 3.5, called "Data Grids Tour."
The Tools panel shown in the demo includes a Data Grid tool below the Table Field and above the Pulldown Menu tools; the Tools panel in the demo version of Revolution Media 3.5 that I am using has, in place of this Data Grid tool, a List Field tool.
Have Data Grids been pulled from Media 3.5 perhaps?
Edit: Perhaps they have, for the demo stack fails to work: card 4 does not load anything to the data grid in steps 1 to 4 and step 5 returns the following execution error,
Disappointing.card "Table": execution error at line 49 (Handler: can't find handler) near "resetList", char 1
Further edit: Just downloaded RevMedia 4.0.0 Build 910. Here, too, there is no Data Grid tool. Strange.