Is Table Overhead Bad

[itledi]

I have a MySQL database that hold information temporarily, and any information inserted in will either be deleted in the next couple of minutes, or information 48+ hours old will be deleted daily with a cron script I wrote.

I'm noticing that I always have a considerable amount of overhead to this table.

Is overhead a bad thing? And if so should I do something about this?

It seems if I click on optimize table, it removes the overhead. Should I consider adding at the end of my cron job a command to optimize table after deleting the old information?