Welcome to FT!

I take it you are going coach. If you had a sleeper, you would be guaranteed to have an outlet in your room! If the coach is refurbished, you should find an outlet at each seat. If it has not, there are only 2 per coach. (I've had both on my trips this month.)

When the coaches were built 30 years ago, not everyone had laptops, cell phones, iPods, DVD players, etc... - so 2 per car were enough for the cleaners.

If you find there is not a plug at your seat, you can find some in the Lounge car - but remember every other person in the train may be trying to do the same thing!