authorization group

Hi Experts,

May I know the T-code to view the content of exsiting Z authroization group? for AFAB T-code, what's the T-code to assign authorization group to this t-code?

The t-code to assign authorization group to user ID, currently I find we can only assign authorization object in PFCG, under which situation we have to define authorization group?

I have one customized table ZFI003, I want to restrict this table to few users, what steps I need to do?

I have one set (GS03) ZFI001,  I want to restrict this table to few users, what steps I need to do?

Thanks