Do you just lay the mat down on the table or do you adhere it in some way?
Rookie team in MA
Do not attach your mat to your table. At your tournament, mats will not be adhered to the table in any way. They may have just been rolled out the day of your tournament and may still have ripples in them and the ends may be curled up a little (which can be a surprise to rookie teams). Also, be aware that tournament tables (all tables, in reality) are often slightly different sizes, may not be level, may have knots and bumps under the surface or along sidewalls, etc. This is one of the main things new teams may not be thinking about. The robot can be affected by table surface differences - not foam v. plywood but any table to any other table.
One thing we encourage teams to do is . . .to partner up with another team in their area to offer a "table exchange". Not literally exchanging tables but offering to let another team use their table (with privacy) and vice versa to see how the robots respond under different table conditions. Another thing we recommend is to turn your mat around on your table to see if that might affect your robot's performance, put a book or something small under your table to make it less level or maybe a little wobbly, and if you are using a light sensor, try your robot under different lighting conditions.
The more your team puts the robot to the test, the more reliably it will perform despite the table variations at the tournament. Also, we recommend that the team (or one team member) becomes expert at knowing if the mission models are built properly and then look at them carefully before they run their robot on each tournament table. Twice at World Festivals we have found mission models with problems, which luckily we were able to point out to the referees. Also, make sure your team's mat is up against the south wall and is centered east to west (according to the field mat placement rules). Then when you get to the tournament, the team should inspect the mat placement to make sure it is positioned according to the rules.
We hope this information is helpful to you!