This is what I did today (so far). I have been having pain in my right shoulder from sewing--partly because I am reaching up to guide the fabric. My machine has been sitting on a piece of 3/4" plywood that is screwed to an old kitchen table. About 2 feet of the plywood hangs over the end of the table, so I decided to cut a hole in the top and move the machine down so it is level with the table top. It's not fine carpentry, but it does the job. I haven't sewn on it yet, but I'll let you know if it works. The cutting mat I cut is about 8 years old, so I wasn't concerned about ruining it. The blue in the last picture is painter's tape. I have been using it to hold the table on my Bernina for a number of years (the pins broke off). I decided I would use it to hold down the cutting mat so it is exactly level with the bed of the machine.
I just used plumbers tape (it's metal) to hold the stand of the machine. Like I said, not exactly fine woodworking. If I find that it is too jiggly, I can attach the piece of plywood that holds the machine in place with actual wood and L brackets.
First iteration, not so good--blue painter's tape has too much texture so the fabric doesn't move smoothly.
Second iteration was with the plastic you can buy on a roll at fabric stores to put over tablecloths--better--a bit more slippery but not flat enough.
Final iteration (for the moment anyway) I used template plastic and cut a hole for the needle and feed dogs. I'll try it again and see if I need to change it one more time.