Next week I have to go from one end of the country to the other via train. I'm wondering what the etiquette is behind food- can you take food with you or do you need to buy it from the shop on the train itself? I remember the last time I went, people were having bottles of wine (shared) and whole picnics when they were on the table. That was about 5 years ago now so I was wondering what you can and can't take?