Help adding rows to each other in data table

we can do it with the help of a group by

prepare the report table with build datatable (configure two or needed coumns)
Assign activity
LHS: dtReport | datatable
RHS: YourOriginDataTable.Clon

then use again an assign Activity
LHS: dtReport

(From d in YourOriginDataTable.asEnumerable
Group d by k=d(0).toString.Trim into grp=Group
Let s = grp.Sum(Function (x) CInt(x(1).toString.Trim))
Let ra = new Object(){k,s}
Select r=dtReport.Rows.Add(ra)).CopyToDataTable

Also have a look here: