Does anyone know where I can rent tables, chairs, tablecloths, dishes, etc. for a party in CM?

I can't give you CM specifics but you might want to check your local Wat or Chinese temple --they usually have tables and chairs, dishes, pots and pans, etc, and will rent these out to people provided there isn't already something scheduled.

If the temple does not have the things, villages often have a ladies organization that has a complete set of things for village events which are available to people in the village for marriages, new house ceremonies and funerals. Basic stuff so it might not include table cloths. Some caterers have at least some of what you need.

Thanks for the ideas. Does anyone know of a caterer in CM?

Bake n Bite and other restaurants cater. Look at the ads in City Life and you will probably find some others.