New Columns with Specific Row Values from other Columns in Multiple Excel Files

Charcho, check this

Output (first few columns)

Change folder addres in Source step to folder with your excel files

let
    Source = Folder.Files("c:\Users\abc\Downloads\PowerQueryForum\Charcho\"),
    FilteredExtension = Table.SelectRows(Source, each ([Extension] = ".xlsx")),
    TransformedContent = Table.TransformColumns(FilteredExtension, {{"Content", each 
        [   a = Excel.Workbook(_){0}[Data],
            // T = BinaryToTable{0}[Content],
            T = a,
            R = [ Fruit = T{0}[Column1], Year = T{2}[Column1] ],
            RemovedTopRows = Table.PromoteHeaders(Table.Skip(T, each not List.Contains(Record.ToList(_), "jan", Comparer.OrdinalIgnoreCase))),
            FilteredActualYear = Table.FirstN(RemovedTopRows, each not List.Contains(Record.ToList(_), "jan", Comparer.OrdinalIgnoreCase)),
            FilteredOutDiffAndTotal = Table.SelectRows(FilteredActualYear, each not ([Column1] = null) and not (List.Contains(Record.ToList(_), {"total", "diff"}, (x,y)=> List.AnyTrue(List.Transform(y, (w)=> (Text.Contains(Text.From(x), w, Comparer.OrdinalIgnoreCase))))))),
            RemovedBlankColumns =
                [ blankCols = Table.SelectRows(Table.TransformColumnTypes(Table.Profile(FilteredOutDiffAndTotal),{{"NullCount", Int64.Type}, {"Count", Int64.Type}}), each [Count] = [NullCount])[Column],
                  removed = Table.RemoveColumns(FilteredOutDiffAndTotal, blankCols)
                ][removed],
            RenamedColumns = Table.RenameColumns(RemovedBlankColumns,{{"Column1", "Numbers"}}),
            MergedColumns = Table.CombineColumns(RenamedColumns, List.FirstN(List.Skip(Table.ColumnNames(RenamedColumns)), each Text.StartsWith(_, "Column")) ,Combiner.CombineTextByDelimiter("", QuoteStyle.None),"Titles"),
            RemovedSquareTitles = Table.TransformColumns(MergedColumns,{{"Titles", each Text.Trim(_, {"▪"}), type text}}),
            RemovedColumns = Table.SelectColumns(RemovedSquareTitles, List.Select(Table.ColumnNames(RemovedSquareTitles), each not Text.StartsWith(_, "Column"))),
            RenamedColumns2 = Table.RenameColumns(RemovedColumns,{{Table.ColumnNames(RemovedColumns){2}, "DecPrevious"}}),
                RenamedColumns3 = Table.TransformColumnNames(RenamedColumns2, each Text.BeforeDelimiter(_, "_")),
            Ad_FuitAndYear = Table.FillDown(Table.FromColumns({{R[Fruit]}} & {{R[Year]}} & Table.ToColumns(RenamedColumns3), {"Fruit", "Year"} & Table.ColumnNames(RenamedColumns3)), {"Fruit", "Year"})
        ][Ad_FuitAndYear], type table}}),
    Combined = Table.Combine(TransformedContent[Content])

in
    Combined