Implementing From For Each Row in Data Table code To Linq

feel free to decompose the LINQ to essential activities for analysis and tracing purpose

From row in Excel_Datas (asEnumerable() is missing within the LINQ)
we can use a for each row

All Lets are mapped to Assign Activities

A group by we can handle as done here:

Taken from: [HowTo] Overview on different options for grouping data and processing the groups

we take the distinct values with the DefaulView.ToTable approach and using it filtering

Select DatatableVar.Rows.Add → add Datarow Activity