let
    Source = List.Buffer(Excel.CurrentWorkbook(){[Name="Table1"]}[Content][Column1]),
    folder = 
        Table.Buffer(
            Table.SelectRows(
                Folder.Files("ваш_путь_к_папке_с_файлами"), 
                (x) => List.AllTrue({x[Attributes][Kind] = "Excel File", x[Attributes][Hidden] = false})
            )
        ),
    f = (cat as text) =>
        let 
            file = 
                try 
                    List.Buffer(
                        Table.PromoteHeaders(
                            Excel.Workbook(
                                Table.SelectRows(folder, (x) => Text.Contains(x[Name], cat))[Content]{0}
                            )[Data]{0}
                        )[#"Выручка по заказам, ₽"]
                    )
                otherwise null,
            out = if file = null then null else [cat = cat, #"30" = List.Sum(List.FirstN(file, 30)), #"100" = List.Sum(List.FirstN(file, 100))]
        in out,
    txf = Table.FromRecords(List.RemoveNulls(List.Transform(Source, f)))
in
    txf

Source = List.Buffer(List.RemoveNulls(Excel.CurrentWorkbook(){[Name="Table1"]}[Content][Column1])),