Adding a class with Generic Lists inside a Generic List

So I have this class for character dialogs and I’m building a set of Lists using it

class ScriptStep {
	var stepType : StepType;
	var subScript : List.<ScriptStep>;
	var stepDuration : float;	
	var stepTransform : Transform;
	var audioClip : AudioClip;
	var textLine : String;
	var stepAction : function():void;
	var stepActionFade : function(float):void;
	var stepSelectedObject : Obj_Properties_Class;
	var stepPlayerTask : PlayerTaskList;
	var stepWifeTask : WifeTaskList;
	var stepBurglar01Task : Burglar01TaskList;
	var cooperateScript : List.<ScriptStep>;
	var refuseScript : List.<ScriptStep>;

Everything is working well until I realized that by adding those 2 extra variables in the class:

    	var cooperateScript : List.<ScriptStep>;
    	var refuseScript : List.<ScriptStep>;

My .unity file size changes from 600k to 100Mb and the game takes ages to run when I press “Play”. Everything runs fine but its like I added a huge slowdown.

If I remove those 2 variables in the class everything goes back to normal.
I would like to understand why this is happening. Am I typing the variables badly? Am I not allow to add a list inside another list?

Any help very appreciated!

You have a list inside of a list. Think of two mirrors pointing at each other. Each of the images within another image is a representation of your list-ception. I think the only reason it goes to 100MB is because the is the buffer limit. If you didn’t have an overflow limit. Putting a list inside a list would cause your computer to crash.