Oh its not easy to use metatables the way I thought! Do you think this approach will not work in large projects? or will it be confuse even to debug? I am trying to learn how to use metatables not just on one file I have search how to use it but fail ,I don't see tutorials that explain how to use it...

I am Pretty New to meta-tables and wonder why this doesn't work can anyone help me solve this small problem. also searched web and did not find anything related to it.
Goal is to have one Meta-table and have multiple tables added to the master table from different .lua files
can this be possible?