Error occurs when entering random data.
This behavior is described on IBM support page it is data base related
Defect ID - QAT-18765
Fix:
Narrow down the search for problematic data, based on the message you get. Then, you should check table cells constraints and enter data that fits those cells.
STATUS:
When error window pops up, TDP will provide user friendly message: "Some of new data exceeds table cells formatting limitations."
Waiting for fix in the future deployment of Toad Data Point.