let
Source = Excel.CurrentWorkbook(){[Name="Table2"]}[Content],
Group = Table.Group(Source, {"Name"}, {{"All", each Table.Transpose(Table.SelectColumns(_,"Account No")), type table}}),
Expand =
let
Cols = Table.ColumnNames(Table.Combine(Group[All])),
NewCols = List.Transform(Cols, each "Account Nr " & Text.From(List.PositionOf(Cols, _)+1)),
Expanded = Table.ExpandTableColumn(Group, "All", Cols, NewCols)
in
Expanded
in
Expand