The code on the Table View documentation will allow for updating existing rows/data.
You can now find (and download) an example of a sample rule that supports all three actions (Update existing data; Delete rows; Insert new rows/data) on the Partner forum - Table Views - May 2022.
This rule works on the assumption that the table has a primary key column but can be updated to suit different cases. In case you have any questions on this topic (including the sample rule), do please make sure to watch the recording.