Multiple vendors roam about in the coaches selling poha, idli, vada, upma, vadapav, kanda bhaji, tea, coffee. Quality of some of the items is not just good, its awsome. For the first time I have seen idli-vada being served with sambar in a train, and sambar is amazing, much better than you get in restaurants.
Surprisingly, from Sangli to Pune, no vendor turns up and passengers have to remain hungry if they have not stocked up while boarding.