Combining multiple rows of data into a single row

Dear members,

I have a set of raw data organized by items (vertically) and months (horizontally).
I would like to group these items into categories (with the data summed up).

I tried using pivot tables, but does not seem to do what I want it to do.
I have attached a sample of what I am trying to achieve here.

Could someone please kindly have a look for me and direct me to right right place?
Very much appreciated.

Thank you.