well, I think sticking to one table is the way to improve. The crucial thing that you learn at first is reads. Once you learn to make good reads, you can use those reads to act against certain opponents in a different way. The cards become less of an issue because you are playing the player. You make far better decisions when you have a read on players and, as a result, it can earn you extra money or save you money. You can only really learn this when starting out by playing one table at a time and really focussing on this.