I've tried to maintain your variable names, and aimed more for understandability than brevity:

while ($tempData = <DataIN>) {
        chomp($tempData);
        $listTemp = [];
        @$listTemp = split(/,/ , $tempData);
        push (@listFinal, $listTemp);
}

return @listFinal;
[download]

Read one line at a time, the text of the current line is stored in $tempData. Remove the trainling newline from $tempData.

Generate a new, empty anonymous array, $listTemp is a reference to that array.

Split the line up at the commas, this gives you a list of values. Those are stored in the Array that $listTemp points to.

Now, push $listTemp into the resulting Array.

--
Brigitte    'I never met a chocolate I didnt like'    Jellinek
http://www.horus.com/~bjelli/         http://perlwelt.horus.at