Originally Posted by
spaley
What is the closest area of the city by train for dinner? In order to return to the hotel, do trains run late at night?
Closest tourist area would probably be Tsim Sha Tsui or Mong Kok but travelling from the Marriott at the airport, it's just easiest to go to Central (Hong Kong station). Besides the Elements mall, there's nothing by Kowloon station and really, if you're at Elements you could pretty much be in any first world mall.
As for the timetable for the Airport Express, you can find it
here.