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:
https://docs.automic.com/documentation/webhelp/english/AA/12.3/DOCU/12.3/Automic%20Automation%20Guides/help.htm#Script/Reference/ALPHA2RUNNR.htm?Highlight=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#"
This returns:
U00020408 File: AOFTGJW RunID: 0000000168962400
This runID then can be reviewed and, if completed, the files can be deleted safely.