This Pace chart shows SPL x Tempo combinations for a 25 meter pool. It assumes the swimmer will push-off and glide for 5 meters before beginning Stroke #1.
You may have in mind some fixed number for any one of the three variables (SPL, Tempo, or Time) and then you can look at you options for the other two variables connected to that by the chart.
For example, Juan wants to achieve a pace of 24 seconds per 25 meters. His SPL range is 17-19. So, looking at the rows that correspond to SPL 17-19 and 23-24 seconds, shows him that he must train with Tempo in the range of 1.10 seconds (with 19 SPL) to 1.25 seconds (with 17 SPL).