The details of what you should do depend on exactly what you mean by "If there is no data in the table..."
If your script needs to check to see if there are no records at all in the table, have it go to a layout based on that table and then Get ( TotalRecordCount ) will return the number of records in that table.
If you want to see if there are any records in that table that are linked via a relationship to the current record on your current layout, IsEmpty ( RelatedTable::NeverEmptyField ) will return True if there are no related records.
To keep the "no records" dialog from interrupting a script that performs a find, put:
Set Error Capture [on]
just before the Perform FInd script step.