Per the "Sparsely populated records" section of https://wave.google.com/wave/#restored:search:jira,restored:wave:googlewave.com!w%252BWU4iAICkI.1, this must be possible:
Range range = table.getRange();
Remember to handle List<SomeEntity> as well.
Ideally this will include throwing runtime exceptions when client code calls the getter for an unrequested property, but perhaps that will need to be spun off to a separate M3 task.
|This issue is not fixed in 1.1.0.M3 + GWT 2.1 M3||Resolved|