let
    from = Folder.Files(Excel.CurrentWorkbook(){[Name="adres"]}[Content]{0}[adres]),
    filtr = Table.SelectRows(from, each not Text.Contains([Name], "свод"))[[Content]],
    books= Table.TransformColumns(filtr,{{"Content", each Table.PromoteHeaders(Excel.Workbook(_){0}[Data])}}),
    renamed = Table.TransformColumns(books,{{"Content", each Table.RenameColumns(_,List.Zip({Table.ColumnNames(_),List.Transform(Table.ColumnNames(_), each if Text.Contains(_,"Класс") then "Класс" else _)}))}}),
    list = List.Distinct(List.Combine(List.Transform(renamed[Content], each Table.ColumnNames(_)))),
    expand = Table.ExpandTableColumn(renamed,"Content",list),
    to = Table.SelectRows(expand, each ([ФИО обучающегося] <> null))
in
    to