Phil Gordon gives some great online poker secrets in regards to how to play when you are the big stack at the table in a poker tournament:

1. Never limp into a pot
2. If the blinds consist of tight players with average stacks, play almost any hand in position
3. Punish limpers with big raises from position when you think they are weak
4. Call from position more often when an opponent with an average stack enters the pot with a raise
5. Rarely, if ever, confront a short-stacked opponent without a premium poker hand
6. Try to win more hands before the flop