The message is generated by the MS SQL ODBC driver (as it says in the error message), so either the database cannot handle data that large (perhaps the 'text' column definition is limited to a certain size?) or the ODBC driver can't handle it.

I'd check the table definition to be sure it's set up to handle that much data. If it's correctly set up, I would check your original assumption that it's only sending 23k or whatever bytes of data for that one field.