I usually forget to warm the plates until the meal is almost ready, so I learned to just place a stack of plates in the microwave with a serving dish on top with 1/8"-1/4" of water in it. Heat a minute or two, and the plates are warm but not too hot to handle. Or, bake potatoes or cook veggies in the 'wave, putting the stack of plates underneath.

The rice would be a moist heat and would damage the table finish, you would need to use a charger.

Thank you for all the great ideas! One of my sister's challenges is that her dinnerware is Corelle - I guess it doesn't do well in the microwave? I've shared all these ideas with her and she's considering several :) Thank you again

I always preheat dinner plates in the oven. Our daily dinner plates are stone ware, special occasion is china, all are oven proof. I never worry about how hot the oven is. I have never broken a plate by heating it in the oven.

We have never had any table damage putting the hot plates on just a tablecloth on the table. Sometimes dh uses place mats on top of the table cloth.

I have never used Corelle, I have no idea if you can put it in the oven, but as it is thin, I do not know how much heat it would hold.

I married into a family that never warms their plates. Every meal is pretty cold by the time it is plated and on the table. Yuck.

I've been using my Corelle in the microwave for at least 40 years. It can go in the oven too--I don't remember the maximum recommended temperature, I've stuck to 350° or less--though not under the broiler. If you put one on a HOT burner, it will break with a resounding crack! (I only had to learn that lesson once.)

This information is from the Corelle website
Use & Care
Corelle® plates and bowls are made of Vitrelle® glass. Mugs are made of porcelain or stoneware as noted on the package. Please review information on bottom of items prior to use.
Corelle® products can be used for serving and re-heating food in microwaves or pre-heated conventional ovens up to 350° F (176° C). To warm empty dinnerware for serving, use pre-heated conventional ovens only. Porcelain and stoneware mugs are microwavable.