Personally, I think popping out of the wall bracket is only one of the possible consequences. I think, over time, the banging about could strip out the bracket attachment to the wall, and I'm not sure the Scamp
leg hardware is up to the challenge, either.
If you are determined to do this, you could keep the tabs firmly anchored in the brackets by drilling and running a thumb screw though bracket and tab. You could also screw a tight-fitting rubber chair foot to the floor and pop the table leg into that to keep it from bouncing around.
The high-end solution would be a hydraulic pedestal mount (photo courtesy of Paul "grimjed" and posted here