TopTablePlanner is an online tool that helps you to quickly arrange and create your table seating plan. You can rearrange guests and tables as much as you like and create different versions to see what works best. Just create your guest list (you can import existing lists from Word or Excel), add some tables, and then drag and drop guests onto the plan. Once you’ve arranged your plan you can then output a PDF ready for printing. You can even print place cards!
See the website for your free trial.