BIRT report - group rows


I need to make a BIRT (.rptdesign) template for Invoices where I must separate Products and Services in a table to a separate groups.

For example table could look something like this:

Table has a group element that could work as a solution, but I have no experience with group.

  1. Is it a correct approach to use table group element for this? If not is there any other alternatives?
  2. Would I have to modify the data set/SQL used to retrieve invoice list of items?

Thank you in advance!