let
Source = Excel.CurrentWorkbook(){[Name="T_Data2"]}[Content],
AjtIdx = Table.AddIndexColumn(Source, "Index", 1, 1, Int64.Type),
UnPivot = Table.UnpivotOtherColumns(AjtIdx, {"Index"}, "Attribut", "Valeur"),
Table = Table.FromRows(List.Split(UnPivot[Valeur],5), {"Descriptif", "Prix U", "Qté","Prix HT","TVA"})
in
Table