Try it out, what's the worst that can happen? I think you should also stress test the table - put the iMac on it, then sit down on the table to add your weight - if it can withstand that, you know it'll take the iMac no matter the air temperature variation (btw., stress testing gone wrong is how I got to be a corpse). If the table breaks, no big deal - huge razor sharp shards of glass will slash down on your legs... but so what - I've seen many people without legs and they are alive - as long as you have an ambulance not too long after, cause bleeding can be a problem. Good luck!