If you do not need for the log file for the moment, you could just remove the option in the batch file (command line) which will stop it's creation.
Alternatively you could use this option:
Which will overwrite an existing file with empty one and save log data for each session. (not append like the >> option)
This will keep the file smaller. NOTE: If you run a session for weeks at a time then it will still grow large.
You could also add the following to your batch file if these files are also not needed by you:
This will delete these two files which can grow to large sizes.
Replace 'filename' with real names of file.