Marcel Barang has the noble goal of translating and publicizing modern Thai prose literature via his website (English and French versions). In the preface to his anthology The 20 Best Novels of Thailand, he explains why much Thai literature is not very good by Western standards (“Too many Thai novels, I found, are dripping with honey and rosy beyond belief”) and why there is so little available in translation. And at the bottom of the Menu page, there is a link to the Thai On-Line Library – Bitext Corpus maintained by Doug Cooper, which has parallel translations:
The Thai Bitext Corpus is a collection of Thai and (mostly) English parallel translations or bitexts. The complete library can be searched for usage examples, or individual texts can be read in a variety of layouts. Bitext searches allow either Thai or any available second language (L2), and use an extended AltaVista ‘advanced match’ syntax.