Is it ok to have a robo dwarf hamster in a habitrail ovo pad?

That will be fine! Ask the seller. by the way hamsters can climb vertically in tubes. They're pretty good at it. I personally don't think your should put hamsters in those sort of cages and instead put them in a basic/classic cage/tank, as they have more room to play/ run/ dig/ climb. You can add lots of cool stuff like toilet tubes and boxes to a normal tank/ cage. Hope this helps.