Column Manipulation

That format isn't the best for analysis but here's one way to do it in the query editor with a column that has a custom list of records.  To see how it works, just create a blank query, open the Advanced Editor and replace the text there with the M code below.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45W8k3MTlXSUfLIz0tJBNLBiTkgrqGRsVKsTrRSZGpiEZBrZGBoBpIsSSwByYZEKMXGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t, Column2 = _t, Column3 = _t, Column4 = _t]),
    #"Added Custom" = Table.AddColumn(Source, "Custom", each {[Col1 = [Column1], Col2 = [Column2]], [Col1 = [Column3], Col2 = [Column4]]}),
    #"Removed Other Columns" = Table.SelectColumns(#"Added Custom",{"Custom"}),
    #"Expanded Custom" = Table.ExpandListColumn(#"Removed Other Columns", "Custom"),
    #"Expanded Custom1" = Table.ExpandRecordColumn(#"Expanded Custom", "Custom", {"Col1", "Col2"}, {"Col1", "Col2"})
in
    #"Expanded Custom1"

Pat