Could you translate this sentence into other languages of your choice? (you can also do that in a comment).

No, in fact, I can't. Its "shop-language" of waiters in restaurants.

But I can explain:
«Et pour Monsieur ?» means that I enquire about what Monsieur will have. I might address him directly or his wife...so she might be the one expected to reply, but the second leg of the sentence hints at the fact that Monsieur himself responds, since « Allez ! » means he wants to indulge, although a blanquette might not be very reasonable for his diet...

Une « blanquette de veau » is - my favourite dish - a kind of calf's stew in a thick butter sauce with mushrooms and « grelots » (small) onions and served with rice or potatoes.

I made many different variants of this sentence http://tatoeba.org/epo/sentence...rom=fra&to=und having fun at all the possible answers...

Quite interesting, and probably delicious, too! :)
I see it is indeed a challenge for translators.
Thanks, I'll see whether I can translate any of these sentences (after giving it further thought). A bientôt !
Bonne nuit !

I commented a few of them so you can have more context.

>I see it is indeed a challenge for translators.

Indeed, I think the protocol in restaurants in France is so specific that it must be difficult. It wouldn't come to my mind, for instance, to address waiters in London or New York as I do in Paris. Even in Brussels.
The big difference between France (and Switzerland) and all other countries, in my experience, when it comes to waiting, is that, to the dismay of most foreign tourists, for instance, French and Swiss waiters are professionnal people, who have a high opinion of their art and status.
In other countries, waiting is considered a student job or a temporary position just to survive while awaiting for better days. In France and Switzerland, waiting is a career and these countries feature great waiting schools (Écoles hôtelières) where waiters learn how to carry 5 hot plates on one hand while smiling and answering long convoluted questions from idiotic customers who have no idea how difficult and painful that is...
I think that is why foreign tourists, paradoxically, perceive parisian waiters, for instance, as rude. Actually, it's the waiters who think the customers are rude and don't respect their art, spending 10 minutes ordering 3 different kind of cokes while the waiter is full of work. Waiters must be respected and when you call them, you'd better know why.
If you ever have the opportunity to indulge in Paris, go have a delicious blanquette in one of the great Brasseries (my favourite is Terminus Nord, in front of the Gare du Nord). The staff there has no less than 5 different ranks and the waiting is like a ballet. It's not only delicious, it's fascinating. I think this art will disappear and I will miss it. In Brussels or Berlin, apart from a few select places, waiters usually are unkempt badly paid students, who forget what you ordered, don't clean your table, and bring you something else, usually cold, and everybody have their plates at different times...

Thanks, I wasn't aware of that.
Yes, in Israel it's the same, waiting is usually a between-the-jobs occupation.

I thought that the Écoles hôtelières serve to teach you how to be a good chef or run a proper hotel rather than how to be a waiter - or at least, that someone who finished such school will not be what I would call an "ordinary" waiter :)