Literally, I mean. The Chinese characters for pak choy, or Chinese cabbage (白菜), can also be pronounced to mean “100 types of prosperity and luck.” Which explains why this vegetable is a favourite of Chinese jade carvers, though their creations are usually somewhat smaller than the metre-long specimen pictured below.
I’m not sure about the second hanzi, I think 菜 just means vegetable here (it could possibly mean prosperity too in an idiomatic sense maybe, I don’t think it does, but I’m no expert), but I do know that 白is white, not hundred. 百 is hundred. I would think 白菜 is more along the lines of ‘white vegetable.’