There are 40 dishes ranked on this page. The lightest is Moo Ping at 130 kcal per 1 skewer, the heaviest is Khao Soi at 700 kcal per 1 bowl, and the average lands around 387 calories a serving. 11 of them come in under 300 calories, and 4 are 600 or more.
That spread is the whole point. Two dishes off the same menu can be 570 calories apart, which is more than most people's entire daily deficit. Knowing which is which costs you nothing and changes the outcome.