voici la solution
Dim plg As Range
Set plg = ThisWorkbook.Worksheets("test1").Range("A3:F9")
Workbooks.Open ("Y:\test3.xlsx") 'fichier 2
With Worksheets("test1")
Lig = .Cells(.Rows.Count, 2).End(xlUp).Row
.Range(.Cells(Lig + 1, 2), .Cells(Lig + plg.Rows.Count, plg.Columns.Count + 1)).Value = plg.Value
End With