As it returns every log and exception from Execute, that will be saved to LastText column of tblScheduledItem. If there were a lot of exceptions, that will create a very long string that will be read from database, and then create a long string in application.
Exceptions should be logged to log, and the Execute should only return the summary of the execution (for example, processed 10.000 urls, 9500 successfully, 500 with errors
Related https://vimvq1987.com/Fix-your-Search-Navigation-please/