Why not the full range? Is it uneconomical to stock the full range or is it somehow felt that by only stocking limited items people will be put off from travelling - which seems to be the main aim of the government and rail companies at the moment? I can't imagine many people will be put off by a limited trolley service. Or is it because if you stock loads of items people have an excuse to not wear theirmuzzlemask for a long time?
Probably because fewer people travelling means lower sales. This has implications for date code control on short dated product, e.g. sandwiches, cakes etc.