Table's transposing

You can finish the trasformation by just clicking UI,

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("pVLLDoIwEPwVw5kmIJKUgyeMF4IhXgmHAgvS8DA8Dv692154KqBkszudbieztL6vKKqStVBkMQLbI/rRQDAMSk39dieOdZ5sHLCdUk2b0A7Hb9IcqL5id01bFVDj2qsrDlHrspKlkuCsxJxAiLlggmHPWuLXIsO7UuZ8dfcj36XSFRN2oJUuMIg5GoccZ+N9CyEYjgV/DKEUbVMiFl3m9eEsQlBcsVs10Cw0071zAoILKzPItxwh01fVe9Rk1bAK2WQuSwxzj7mRyxTBtYb478t49ELC7EpZ+RmnxRQEbw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t, Column2 = _t, Column3 = _t, Column4 = _t, Column5 = _t, Column6 = _t, Column7 = _t, Column8 = _t, Column9 = _t, Column10 = _t, Column11 = _t, Column12 = _t, Column13 = _t, Column14 = _t, Column15 = _t, Column16 = _t, Column17 = _t, Column18 = _t, Column19 = _t, Column20 = _t, Column21 = _t, Column22 = _t]),
    #"Merged Columns" = Table.CombineColumns(Source,{"Column1", "Column2"},Combiner.CombineTextByDelimiter(";", QuoteStyle.None),"Merged"),
    #"Transposed Table" = Table.Transpose(#"Merged Columns"),
    #"Replaced Value" = Table.ReplaceValue(#"Transposed Table","",null,Replacer.ReplaceValue,{"Column1"}),
    #"Filled Down" = Table.FillDown(#"Replaced Value",{"Column1"}),
    #"Merged Columns1" = Table.CombineColumns(#"Filled Down",{"Column1", "Column2"},Combiner.CombineTextByDelimiter(";", QuoteStyle.None),"Merged"),
    #"Transposed Table1" = Table.Transpose(#"Merged Columns1"),
    #"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table1", [PromoteAllScalars=true]),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(#"Promoted Headers", {";itemid;Customer;ProjectManager"}, "Attribute", "Value"),
    #"Split Column by Delimiter" = Table.SplitColumn(#"Unpivoted Other Columns", "Attribute", Splitter.SplitTextByDelimiter(";", QuoteStyle.Csv), {"Attribute.1", "Attribute.2"}),
    #"Filtered Rows" = Table.SelectRows(#"Split Column by Delimiter", each ([Value] <> "")),
    #"Split Column by Delimiter1" = Table.SplitColumn(#"Filtered Rows", ";itemid;Customer;ProjectManager", Splitter.SplitTextByDelimiter(";", QuoteStyle.Csv), {";itemid;Customer;ProjectManager.1", ";itemid;Customer;ProjectManager.2"})
in
    #"Split Column by Delimiter1"