you can use a small piece of ply on the folding table, it will absorb alot of the vibration especially if the machine is over the legs on the right side. If you use plywood for the top with file cabinets or elfa drawers you can cover the board with fabric and clear vinyl or a flannel back table cloth. I now have a sewing desk that my machine fits in. But before that I used one of these which I still take to me to sewing classes.
http://sewingmates.com/ The thing I like about this table is that it will fit more than one sewing machine. Since most of us tend to get more than one.