Fix your pasta machine with a bar clamp
TLDR: Consider just holding down your pasta machine with a (set of) adjustable bar clamps; they're easier to use and it makes your pasta making experience more enjoyable.
Pasta machines usually come with awful clamps. A different Adam notes this is the key flaw of a high-end highly-recommended pasta machine:
While I was able to successfully clamp the pasta machine to the table, the table itself was far from stable and wobbled every time I tried to crank the machine.
This lines up with my experience, where I often find the pasta machine making its way across the table over time, or rotating in various axes at the clamp point. This causing a rip in a big pasta sheet is extremely frustrating, and probably up there as my biggest gripe with pasta machines too!
The official clamps are also surprisingly not cheap:
A quick adjustable bar clamp is both far easier to attach and grips the machine much better. You can also put one on each side or use one bar clamp and the original clamp to prevent the machine rotating at all.
The "well-known" brand here is Irwin Quick-Grip clamps, which often can be had on sale from Screwfix or Toolstation for ~£6.
(Of course, being multi-purpose clamps, these also come in handy for other things. I do feel like having a set around the house does come in surprisingly handy. E.g. I've also used mine to clamp together a worktop and some stands to make a temporary garden table, and of course used them for general DIY tasks.)
P.S. If you have a pasta machine and you're tired of making pasta with it, consider making some dumplings with my recipe!