All these table lifts are basically the same (except for Handy, which is made in the US) and are made in China, probably in the same factory. I have one similar to the pic you posted, its rated for 1,000 lbs. and I've ridden onto the lift for years. As long as you have the side pieces installed (so you have a place to put your feet) you'll be fine. I imagine the admonishment about pushing the bike onto the lift is a liability thing. Trying to push a 900 lb. bike up the ramp by yourself is going to be more precarious than riding onto the lift, IMO.
Also, I initially had the wheel clamp type chock for the front wheel; however, after riding up, you have to get off the bike, continue to balance it with one hand, while tightening the clamp with the other hand. To make it easier, I mounted my Bike Pro chock to the lift, so now when I ride up, the wheel is locked in place so I can just get off of the bike. BTW, you're going to love having a table lift...so easy to detail and service your bike. Your knees will really appreciate it.