I thought the Scout came with a delrin, not rubber, washer. At least mine did when I bought it in 2010. Reading your question I'm not entirely sure what you're asking, but the purpose of the washer is to flatten the record as much as possible against the platter; it has nothing to do with leveling the table. You should level the table to insure the platter is perfectly level without worrying about the washer.
My experience with the washer has been opposite to Stanwal's -- the washer and the clamp make a tremendous positive difference when it comes to flattening records against the platter. I wouldn't play a record without it.