For 118 bucks you can buy a heavy duty linear electric actuator that would raise and lower the table. I think you are limited to 12 inch movement, but I seldom move my table more then that anyway. It might or might not work for you.
Northern Hydraulics has them in light duty, and heavy duty models. In case you don't know what one looks like, here is a picture I gleaned off the internet.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"