The values given is the refractive index of the following midiums
use this table to give an example of :
about refratctive index
Refractive index of medium A with respect to medium B = speed of light in B/speed of light in A
Refractive index of medium A with respect to Air = μA = speed of light in Air/speed of light in A
Combining these two we can write,
μB /μA = VB/VA
(1) Hence the media pairs will be water to crown glass, water to rock, and so on as water pairs up with each medium. Then crown glass to each other medium except water.
(2) Diamond to ruby or rock salt and so on upto water. Again Ruby to every other medium except diamond and so on for remaining media.