How to add tables inside group element

[info_1017]

I'm new to Jasper and attempting to convert a report that's using a frame layout to using tables.  
This is needed because the cells merge together in excel and it doesn't look good.  I'm hoping if I redesign using the table it will be nice and neat.

I'm getting "Report design not valid : 1. Unknown reset group 'Categ Grp' for variable : Alpha"

Here is that reset group:

     <variable name="Alpha" class="java.lang.Integer" resetType="Group" resetGroup="Categ Grp" 
        calculation="Sum">
        <variableExpression><![CDATA[$F{ProductCnt}]]></variableExpression>
        <initialValueExpression><![CDATA[0]]></initialValueExpression>
    </variable>

This is telling me that I need to get the tables inside of the group element.  How do I achieve this?

I came across a similar issue online  but that that report is only using strings not variables with reset group as I'm using.  Any help would be greatly appreciated.

XML attached