Tables should be used to display data when you need to look up specific values.
The earliest table I remember (quite vividly) is the multiplication table that we were given in elementary school (yes, long before hand held calculators of any sort). I remember it so well that it only took me minutes to reproduce it using Excel.
Choose the two numbers you want to multiply and where they intersect on the table is your answer. The other great (really great) thing about this specific table is that you can see the pattern of addition and subtraction, which takes a whole lot of mystery out of multiplication. (I give total credit to this table for my ability to calculate the tip on a restaurant check in my head.)
A simple, elegant and perfect example of how a table should be used to look up specific values.