You could use sprintf:
in reply to Format question
Of course, you would need to adjust the widths of the fields according to the expected maximum lengths of the data. You should also use appropriate format types (I assumed here that $secv and $title are strings, and $seats is an integer. Different format specifiers may output the same values in different form).
$list=sprintf("%-10s %-30s %d\n", $sec, $title, $seats);
Side question: why do you copy $sec, $title and $seats to different variables? Unless you are doing something else that your snippet didn't show, it doesn't make much sense.