Hamilton signed young drivers' overalls and handed out trophies at the event.
Record-breaking start
Carolynn Hoy, from the Stars of Tomorrow organisation which held the event, said: "We always thought there was something a bit special about Lewis.
"I think he is going to do fantastic (at the British Grand Prix). All the boys have sent on their best wishes and will be rooting for him."
Hamilton has enjoyed a record-breaking start to his Formula One career, becoming the first competitor to finish on the podium in his first three races.
He now divides his time between the family home in Stevenage and McLaren's headquarters in Woking, Surrey.