Your question is "how to secure a monitor to a desk", but I believe the actual question should be "How do I prevent my monitor from falling off the desk". One solution would be to attach it to the desk. But another solution is to prevent the desk from being kicked.
You may be able to accomplish this by placing things on the floor around the legs, such as a potted plant on the floor. You could also place the table against a wall, and put the back of a couch against one side. (No one will walk through the couch!)
Another option is to get a more solid, heavy table that would move very little if accidentally kicked. You could even reinforce your existing table to add weight to it.
A final option is to place the table against a wall, and mount the monitor to that wall. It could be just a centimeter above the tabletop so it is still at an ergonomic height for viewing.