Suppose you are taking part in kart racing. There are several karts/starting positions, f.e. 8, and number of racers, f.e. 30.
Each racer should eventually try out each kart/starting position. The question is to make it in random order, so none would wait too long for his next lap and compete with different racers each time.
The generator below creates racing laps tables. First table shows racers for each lap, in order of karts. Second table shows each racer's schedule - laps where racer participates and kart which racer drives during this lap.