Shy, we'll make it work!
I'm thinking in terms of making a drop zone for everybody with space both on and under a table... on top of the table, you'll see names (online handles) on tape, and below/in front of the table there will be the signs that Catmint made. On top of the tables, tape will divide one person's space from another, and on the ground I intend to use stakes and rope. Ideally, everybody will have some space both above and below (shaded) the tables, depending on how it works out. Normally we just spread out far enough to avoid confusion about which plants are in whose spot, but I don't think we'll have enough room for that. As we've done in the past, look for it to be arranged alphabetically left to right by name (online handle... I'll be near the beginning as "critter" rather than in the middle a "Jill").
Lisa, you mentioned that your car is small... so bring whichever table fits easily (probably not the wooden one I'm guessing).