They have snacks and sandwiches, but won’t be offered proactively. You will need to go to the galley and ask about it. It is nothing to write home about it. If they have leftovers they will be able to serve you a snack meal in-between the main meals. Sandwiches are also provided in economy between meals and as self-serve in the galley. Are quite dry and usually with a piece of cheese and a piece of tomato or lattuce inside.