These files are (O)utput from a job report or (J)CL; they were generated from jobs within the Automation Engine.
You can look at the specific runids by converting them via ALPHA2RUNNR:
Here's an example script that can be placed into a SCRI object to get the runID:
:SET &FILE# = OAOFTGJW.TXT
:SET &ALPHA# = MID("&FILE#",2,7)
:SET &RET# = ALPHA2RUNNR(&ALPHA#)
:PRINT "File: &ALPHA# RunID: &RET#"
U00020408 File: AOFTGJW RunID: 0000000168962400
This runID then can be reviewed and, if completed, the files can be deleted safely.