Power Query Custom Grouping

Dicken You can use the 5th parameter of Table.Group to split this based on the equality of values in Item column.

Table.Group ( 
     Sub,
     "Item", 
     { "T", each _ },
     GroupKind.Local, 
     (x, y) => Byte.From ( x <> "" and y <> "" and x <> y ) 
)

 And since you have the "Total" word in the column Name that can also be used.

Table.Group ( 
     Sub,
     {"Item", "Name"}, 
     { "T", each _ },
     GroupKind.Local, 
     (x, y) => Byte.From ( y[Name] <> "Total" and x[Item] <> y[Item] ) 
)

Thanks, I'll have to work through that, not very good with custom comperers, and have not used 
Byte.From,   will go through it. 
I may have questions, 
Richad. 

Dicken (x, y) are are basically (CurrentGroup, CurrentRow), a group starts with the first row and then based on comparsion between x and y or just y with some condition either rows are kept in the CurrentGroup or a new group is started.

If a boolean operation between x and y return True then a new group is created, if it is False then CurrentRow is added to the CurrentGroup.

Byte.From is used because the accepted values by 5th argument are either 0 or 1, I could have used Number.From as well.

Now in your scenario you could use the following code, but I don't know how your data will look like or if you are even interested in a second local grouping, if you're then previous code is fine but if not then probably this should be enough, it just adds a small overhead that later if you don't like you will have to make Item = null for total row.

let
    ...,
    Sub = Table.Combine ( Group[Count] ),
    ReplaceWithNull = Table.ReplaceValue ( Sub, "", null, Replacer.ReplaceValue, { "Item" } ),
    FillDown = Table.FillDown ( ReplaceWithNull, { "Item" } ),
    Group2 = Table.Group ( FillDown, "Item", { "Count", each _ } )
in
    Group2