Living in Thailand, I see this plant everywhere but I have as yet to find the botanical name. The Thai name means "Millionaire Wilson" which presumably comes from the fact that they look at the leaves for lucky lotto numbers. So I thought of Dieffenbachia amoena "Wilson's delight" which it obviously isn't. I doubt that it is a Dieffenbachia, having looked through hundreds of photos although the base of the leaf stems are sort of variegated and I have found a photo that looks very similar with variegated leaves.
As you can see, it IS an Araceae.