My problem is that my machine is also an embroidery machine. It's a B/L Ellagante and when it gets to stitching with the machine unit on, it can really move things.

I have it presently on a 5 foot folding table that locks, but it's not sturdy enough.. well I mean it holds it alright, but it will get to moving/shaking when it's stitching.

I also have my 301 on that table, so when I'm not using my Ellegante I can use it there. I have about 6 feet to work with here.

I've looked at the thrift store for a old desk, table or sewing machine cabinet, but nothing there and we only have one thrift store.

Does anyone have any ideas? I desperately need help as I don't want it to fall or shake off (yes it get to shaking and scares the bejeepers out of me).

Thank you for any ideas...

I don't have an embroidery machine so can't really help with that but I have had the same problems with machines shimmying and dancing around.
I, now, as of last weekend, have two converted Singer treadle stands that I just love. That cast iron just keeps everything nice and still. Not sure how they would work for what you need, 'though.
lots2do

Mine is in a cabinet, so I don't have that problem.

dont know what it is called but what about the sheets they use in motorhomes so dishes dont slide

used furniture stores are an option, or distressed/damaged in a new furniture store.

I'd be for trying that embroidery machine on the floor to see just how much vibration/dance it really has while stitching...my buddies that have them are usually busy doing something else in the room while there's are running so I don't think you're supposed to have to hold them down...it's possible that yours may need some adjustment? Perhaps one of the plain rubber door mats would help? If your table doesn't have to be put away and you have the wall space, you might attach it to a wall for more stability until you can replace it with a heavier one...then repurpose the folder into a cutting table by raising it to your best height. Oh, I'm thinking you are one lucky lady to have that 301...nice, very nice.

I have a large dinningroom table in my sewing room. I can add two leaves to it and make it larger if I need it. That is sure handy.

I've got a Koala sewing cabinet. My embroidery/sewing machine sits and stays perfect in it. They're pricey but I love it.

Mine is on a computer desk. I just removed the slide out part for the keyboard and it is very sturdy.

I sew on my dining room table. To keep the machine from moving I bought a small roll of the shelf liner thats kind of like rubber. They use the same thing for rugs so they don't slip. You can buy a small roll at Wal-Mart for less then a buck. I cut it a little bigger then my machine and it doesn't move.