Scrabble is a game. Games are supposed to be fun. But there was a seriousness of purpose evident at this year's National School Scrabble Championship in Boston, even before play began. Shortly after he'd reminded the hotel function room full of 5th to 8th graders that the point of the day was fun, John Williams, the executive director of the National Scrabble Association, provided the 200 assembled youngsters with a glimpse of what their futures might hold.