It likely can't be eliminated because the camper has a suspension and rubber tires- but you can do a lot to lessen it.
First things first, you want some kind of triangulation stabilizers. There are a few brand names for this- SteadyFast, JT's StrongArms, UltraFab Eliminators, BAL Something or you can make your own.
Second, get a good between the wheel chock. I like the Rotochocks but they're expensive. Other options are the BAL X-Chocks. Or again, home made w/ a block of wood and a threaded rod.
Thirdly, extra scissor jacks just ahead of the axles.
And finally, you can add supports under the steps.
I'd try these incrementally to see what helps and where you're comfortable. For me, I've gone the first two steps and I'm still not happy (nor is my wife or my very-motion-sick-prone mother-in-law). I can tell when my 50 lb. daughter rolls over in bed. My next step is to get the scissor jacks.