Ok, look, I am not going to do all the work for you here.
Whether or not proc_a gets the inTabA via a parameter or creates it on the fly (as I did for the sake of this example) does not really make a difference for the general technique:
passing and working with the table rather than with single records.
The table-typed variables can be defined via CDS or via DDL (as I showed with the create type .. statement) - that's up to you.
How about you now take the example I gave you and apply it to your problem?
If you get stuck with a specific problem then, we may look into it again.
Have some fun with this over the weekend 