The tastiest of the "rats" isn't a rat, as such. That is the so-called bamboo rat. The local species, the Chinese bamboo rat, Rhizomys sinensis, as its Chinese* and English names suggest, lives in the bamboo groves and it lives on bamboo almost exclusively. It can grow up to 8½-15 inches long (plus tail) and is rather stout.
*竹鼠 (zhú shǔ, literally 'bamboo rat')
Rhizomys sinensis - Kunming Natural History Museum of Zoology - Public Domain Image