That's true, I was being a bit vague. I guess you go for a laptop at least because you expect to do a lot of typing, so I took that part for granted.
Unless you wanted to see what you were browsing, in which case you'd have to hope the train had a plug for the monitor you brought with you.
Using a Chromebook is just like using Google Chrome on a laptop which boots super fast, along with all the apps and extensions you can get for it, mail, google drive (docs), etc..
If you suddenly decide you need some software like Excel, Outlook or Photoshop, you're out of luck, you'll have to use the web equivalents.