As explained on the The Grid Element page, you can create different curves type to add an automation to any parameter of a Rack in the Grid.
To create or delete a new point, use a double click on a line :
Each curves created will generate a menu in the curves tab where you can set minimum and maximum values, scale but also curves type.
Normal: (linear) the numeric value grows linearly from left to right.
Log: (logarithm) the numeric value grows slowly on the left side, more and more quickly towards the right.
Exp: (exponential) the numeric value grows quickly on the left side, more and more slowly towards the right.
Use this option to have a graphic smoother curve