Now, this question can be a little tricky to answer. It truly depends on the particular camping table that you decide to invest in. Here is why. For the models that do not accommodate a lot of weight (such as 25-50 pounds), you will want to be careful about placing such a heavy piece of equipment on top. But, the camping tables that allow the utmost to 100 pounds will easily hold a microwave or grill.
However, the question does not stop there. Not only does the folding camp table need to be durable enough but you have to find a solution to the heat that is dispersed from these appliances. Obviously, the portable tables that are designed to be heat-resistant will not have many issues with this. For those who do not, you could place a heat-resistant material underneath either your microwave or grill (or both if you want them on the table simultaneously). If you ignore this and the camping table is not resistant to heat, you may end up damaging the finish and (in more serious circumstances) making the table unusable.