Paul,
Welcome to Land F/X! The Area Callout is simply an MLeader that has a data field assigned to it. If you want to remove the leader, just select the callout, right click, and select the "remove leader" option. If you would like to add a lot number, say on a second row underneath the area, just double click into the callout, hit enter to move to the next line, and type your info. If the boundary of the lot changes, type regenall (rea) into the command line and the area callout will still adjust appropriately.