When you don't come from a background in weddings, events or banquets you may not know how many people can fit at a 5' round table, or a 8' rectangular table. But we did a little looking and found a great chart that helps with planning how many people to seat at each type of table.
And pro tip: you can screenshot whatever table you are using, throw it into a publisher file, copy and paste it a few times, and voila you have yourself a floor map where you can start plugging in your guests names to their seats!
Extra pro tip: use sticky notes to place guests. Write each guests name on a small sticky note and stat placing them on a seat. If you don't like where they are at simply move the sticky note. No reprinting of the floor plan or easing of a guests name needed.