Step-by-step explanation:
There are 12 games in the population. You need to use a random number generator to choose 2 of these games.
RandomSample[{1,2,3,4,5,6,7,8,9,10,11,12},2]
Let's say the first sample you get is {1,5}. That corresponds to game times of 8 minutes and 7 minutes. The mean game time for that sample is 7.5 minutes. So the first row in your table would be: