Sarah - Roxy does exactly the same - she falls as sleep on the table
Amanda - there is a x-mas show on National Show Center on the 12th of December (next weekend), you cold go and have a look around, talk to chihuahua people there, ask them some advice, I am sure they'll be happy to help (after they have been in the ring). You could get him a show lead there as well, to get him used to walking in that as soon as possible. I have one spare one at home, if you can't find any. And then there is another show at 27th of December (same place), take the puppy with you if you can, he has to get used to the noise and the hall's surface.
Feed him on the table when you can, he has to get comfortable on the higher surface. Always make the show training fun, he should enjoy it
Take him places very busy and loud - traffic, primary schools, shops (pet shops). I walked Roxy on the shelf's in pet shops. Get him use to different people checking his teeth and touching him all over.
Good luck! Let me know if you need anything else, I don't have much experience, only few shows, but I'll be happy to help with what I can..