Table 1: Linear function. For each time x increments by 1, y increments by 2. y=2x.
Table 2: Exponential function. Each time x increments by 1, y divides itself by 4.
y= 0.25^x
Table 3: Quadratic function. Notice how the y values seem to increase by less and less before coming back down in an opposite fashion. This is characteristic of a parabola.