Before resorting to VBScript FOR loops (often much slower than native QlikView statements), try this instead of the current TAB2 code:
LEFT KEEP (TAB1)
FROM (txt, codepageis 1252, embeddedlabels, delimiteris ',', msq);
If you run into trouble (the LEFT KEEP may not like the wildcard), you can first load all files into a single RESIDENT table using the wildcard character, and then LEFT KEEP that table to TAB1. The associations will be maintainbed and no tables will be JOINed.