(A cultural note: eating on long-distance trains is expected (they have fold-down tables and cup-holders), but eating or drinking (other than water) on local trains is an EXTREME faux pas. Don't do it.)
Fret not. There is an on board service, which provides from ice cream over sakes and cold beers a variety of up to 3 bento boxes for sale directly at your seat.
The better option is to buy something on a train station, since the variety is much bigger.
Tokyo (station) is famous for the shop that sells ~ 200 different bentos from the whole country. A short stop makes a delightful train ride even more delightful.
The nice thing in Japan is that eating some fermented fish out of a bento box is completely acceptable, while yakking away on your cell phone is not (you can move out of the carriage if you must make a call).
As for timings. The most impressive for me was 85 minutes from Brussels to Paris, city to city. You must be pretty stupid to use a plane for that.
Yeah. But try going anywhere around Lyon[0] after the nice TGV trip from Paris[0] and welcome to connection hell.
[0] Or any other TGV connected cities.
http://www.tcl.fr/var/tcl/storage/original/application/b8cb6...
Public transportations are often quite good in European cities. When I was in college, it tooked me sligtly more than 3 hours door to door to go from my parents home in a Paris suburb to my University dorm in Lyon. It's not so bad for a trip of nearly 450km.
I love traveling by train, especially in quiet high speed ones such as TGV, Thalys or ICE.
However half the year I am regularly traveling through France for work from one city to another. I love the train, I enjoy it much better than air travel but the time and the stress lost due to running around with a carriage trying to decipher the connections that's going to take me to the tech zoning is... well stressful and time consuming.
I stand by my point: train station to train station is nice but door-to-door ? That's a much less smoother ride.
Paris to Baghdad is about the same distance.
Cities in the US are too far apart for trains to generally make sense. Trains are for freight.
[1] https://www.amtrak.com/content/dam/projects/dotcom/english/p...
[2] https://www.google.com/maps/dir/Pennsylvania+Station,+New+Yo...
The French do like their train strikes though. Maybe let's try Japan. Tokyo to Kyoto: 2.5 hours train, 5 hours by car.
Additional advantage: I can walk around, and get a meal (not sure about the Shinkansen, but the TGV does have a restaurant). And read, or work, or daydream.