A skip counting table lines up two rows of numbers side by side. The top row usually shows the position of a value, like 1st, 2nd, 3rd, and so on. The bottom row shows the actual value at each of those positions, growing by the same amount every single time. That constant amount is called the step, and it is the key to reading any skip counting table correctly.
For example, when counting by twos, the step is 2, so the values go 2, 4, 6, 8, 10. When counting by fives, the step is 5, so the values go 5, 10, 15, 20, 25. Once you know the step, you can identify any value in the table, even one that has been left blank on purpose.