*Construct 2 installer is only 56.1mb in size but it will still expand to 101mb(approximately) when installed. But if you ask me it is already pretty small and well size optimized.
*Construct 2 Lite? I believe there is no such thing.
*I don't really know if I understood you well but if you are asking if the paid version of Construct 2 will reduce the size of your game. Then no, both paid and free version doesn't reduce or increase the size of your game or the Construct 2 Engine. Both are the same except for the export limit, events limit, no family option and etc of the free version. I suggest you read this (Compare Features of Construct 2) for better understanding:
*Again, there is no Construct 2 Lite only the Construct 2 Free Version. The Free Version is for non commercial while the Personal Edition(Personal License) unlocks all features but with a limit of $5000.00 worth of profit of your games and after earning that much you need to upgrade to a Business Edition(Business License) but If you are in an organization or a business then you have to purchase business license and not a personal license.