另一种方式：

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    group = Table.Group(Source, {}, {{"letter", each "Total"},
                                     {"score 1", each List.Sum([score 1])},
                                     {"score 2", each List.Sum([score 2])}, 
                                     {"score 3", each List.Sum([score 3])}}),
    append = Table.Combine({Source, group})
in
    append

或：

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    cols = Table.ColumnNames(Source),
    group = Table.Group(Source, {}, List.Zip({cols, {each "Total"}&
                                    List.Transform(List.Skip(cols), 
                                    (x)=>each List.Sum(Table.Column(_,x)))})),
    append = Table.Combine({Source, group})
in
    append

或：

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    group = Table.Group(Source, {}, List.TransformMany(Table.ColumnNames(Source),
                                    (x)=>{each if x = "letter" then "Total" 
                                    else List.Sum(Table.Column(_,x))}, (x,y)=>{x,y})),
    append = Table.Combine({Source, group})
in
    append