Will this fit a lg mega capacity washer that is 29 inches?

I do not think it will. I have a front load Samsung and it is not the biggest style. The pedestal was too small for it. Thus I don’t think it would work for your machine. I believe Amazon provides the size of the pedestal in their description of the product. Hope this helps.

can this be used for a smaller size refrigerator?

Funny you should ask that. My husband and I were just talking about that the other day. We have one of the small refrigerators you have like for a family room bar or area. We thought we would try it however we have not as of this answer. The span of the opening it would sit on I believe is 25 inches, thus if you would measure your refrigerator, you could tell if it would work. I hope this answers your question. I hope to try it soon.