The Provisions Officer and the others standing by said, "These three are our prince's sons, the young Highnesses."

傍 is páng, alongside — the officials are standing off to one side, which is where officials stand. 子 is zǐ, son, the noun rather than the light suffix the same character carries in words like Idiot. And 小殿下, young Highness, is the rank made small: the little word for small tucked in front of the form of address owed to a prince.

Bajie dropped his bowl and said, "Young Highnesses — what are you all doing with weapons?

And now Bajie puts the bowl down. He ignored being called a monster and he ignored a threat to his life, and the word that finally reaches him is the one that says these boys matter. He also uses the correct form of address immediately, which after two scenes of being told he has no manners is a small quiet joke at his master's expense.

You would not be meaning to fight us?"

莫是 is a softening question-opener — it could not be that, surely not. 哩 is a light closing flourish that gives the line a casual, almost conversational lift. The effect in English is something like "you're not thinking of fighting us, are you?" — said by somebody who has just realised the afternoon might get interesting.