I could be wrong (I won't load this code to test it) but this appears to record not only data that has changed, but also records data in all of the other columns that hasn't changed and it records meta-data about each column in the table as well as some constraint meta-data, and it looks like somewhere between 300 and 400 bytes (can't tell for sure because it's a graphic rather than text) were created for the JSON "Payload" for what? To audit that a single character was added to a single value during an update?
--Jeff Moden
Change is inevitable... Change for the better is not.