This will be concatenated to the same table automatically by a QlikView phenomenon called ... AutoConcatenate. When the next LOAD detects a similar table layout as the last one, the new data will be concatenated to the resident table.
BTW to make it work, drop the add keyword, change FROM $(var) into FROM $(file) and add a NEXT keyword to the end
However, there may be situations where this trick refuses to work (I got a couple of cases that were very RAM-dependent, and some may have been hampered by other things in QlikView not working altogether well)). To make sure that it works under all circumstanctes, you can force concatenation by using a $-sign expansion variable, like in:
LET var = 'file1', 'file2', 'file3'
LET vPrefix = 'tabletemp:';
FOR EACH file IN $(var)
LET vPrefix = 'CONCATENATE (tabletemp)';
The syntax checker will go crazy on the free variable. Don't worry, it'll still work out ok.