There isn't a "for" in Jubula - you do have to know how many datasets / loops you will need. Your point about counting the cells could be possible with the upcoming version though - we have a new action to store a property value (e.g. the amount of rows in a table). You could use this as a comparison or as a dataset (but not as a "execute this check $ many times) - perhaps this will help in this case. Otherwise it could be a case of choosing a certain subset of data that will be representative, or using other cues in the GUI (progress bars, re-enablement of save buttons etc) to help you synchronize.