You can prepare a Datatable with the grouped and sum up values, then you can filter or postprocess it and writing back the result to excel
Assing Activity:
dtGroupSums | DataType: DataTable =
YourDataTableVar.Clone()
Assign Activity:
dtGroupSums=
(From d in YourDataTableVar.AsEnumerable
Group d by k=d("Name").toString.Trim.ToUpper into grp=Group
Let gs = grp.Sum(Function (x) CInt(x("QTY").toString.Trim))
Let ra = new Object(){k,sm}
Select r = dtGroupSums.Rows.Add(ra)).CopyToDataTable
Also have a look here:
[HowTo] Overview on different options for grouping data and processing the groups - News / Tutorials - UiPath Community Forum
UPD-1: Attached Training Resource