Hmmm....I have mine on a metal double computer desk from work. It is pretty substantial but I have noticed on some designs I have to slow the machine down or I have issues.
My serger sits at the other end and I have it on two layers of the waffled cabinet liner for noise muffling. I may try adding some to under my embroidery machine. It never moves but I wonder if it gets a resonation from the table at certain speeds.
Thanks.