"Enjoy your meal!"
I think there is a problem with this sentence: from my time in English-speaking countries (about 3 years in total in Canada, US, UK), I got the impression that it's rarely appropriate/customary to say בתיאבון at the beginning of a meal, whether it's "Enjoy your meal", "Bon appetit", or any other form of this phrase.
When do English speakers say "Enjoy your meal"? In settings like a restaurant, when the waiter comes and gives you a meal. In Hebrew however, the waiter will almost never say בתיאבון (I guess it depends, but it's pretty rare), but they might more commonly say "Enjoy!" (תהנה/תהני/תהנו).
Therefore actually the literal translation might be more appropriate here (it's not accepted), or no translation at all.