I can, however, imagine that the servers would give people a hard time. It's not a very complimentary thing to say, and it reflects badly on all of us with Italian heritage, but generally speaking, the CMs in the Italian pavilion aren't necessary the most polite or friendliest people around. That's not to cast a pall on all of them, but I've found that in a slight majority of interactions there, particularly with the food servers, there seems to be a lack of basic courtesy or an air of condescension that creeps into their attitudes. It's neither here nor there, just something I've noticed that seems to be mostly centralized in that area. So I can see people feeling discouraged in the restaurant.
If you're worried about sharing being an issue, I'd probably recommend just not telling them. Just order your food - there's really no reason to say, "we'd like such and such, and the two of us will be sharing." The only issue to me would be plates, and there will already be small plates on the table from the bread course. If you feel like you want a bigger plate, and they won't give it to you, there's still no reason to worry - the server stands are spread throughout the main floor, so it's easy to just walk up and take your own plate.
What? That's okay to do! Just be coy about it.