The tech gridder is not for adding completely new components, or even extending an example into a tech area (although you can use it for one-dimensional techs).
It is for weaving multiple tech areas together to make a multidimensional tech grid from a single example component
A great example is the missiles in Carrier Battles mod.
There are various tech areas, including "Missile Manufacturing", "Missile Targetting", "Missile ECM".
The component named "Light Nuclear Missile I" is the base model. Researching into manufacturing reduces the supply cost by 5%, and gives you "Light Nuclear Missile II". Researching into targetting instead, gives you "Light Nuclear Missile II" with bonus damage. ECM gives hitpoints.
Researching one level in each gets you "Light Nuclear Missile IV" with one of each.
In total, there are 9 levels in each tech area. In any particular game you will only see 27 Missile components (XXVII), however there are 729 different components in the components.txt file, corresponding to all the different possible research paths.
The tech gridder turns 1 component into 9, those 9 into 81, and then those 81 into 729.
Needless to say, the first step isn't too hard to do manually, but you need automation to go any further
See this quick how-to:
How Does the Tech Gridder Work?