Allows Jack to be leader of the hunters - Jack's in charge of the choir - admittedly, a rather foolish move, as it gives Jack unwonted power, and so sets him up to undermine him in the future, but shows how Ralph is a 'people-pleaser' - wants to keep everyone happy
Also shows how he is a good leader, as he does not gloat about his victory, but recognises that Jack would have been disappointed
At this point, he wants to make friends rather than lead strategically