Merging Columns dynamically

Query_Addict although mahoneypat solution will work and it is a great solution but one challenge I see with this solution is that it will add extra "," commas for blank and null values and also it will only take last 5 columns whereas the following script will ignore first two columns and take all other columns in case it changes in the future and also it will remove null or blank column values and will not add extra commas.

Well done mahoneypat 

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcjQwMFTSUQouyM/PA9IeiXkpOalWQakpIMHMqlQrr9K8zPwiIM83MSXVytDSwhLIBqFYHbBuIyDbOy8zLRVdN0yLkYGBOZDtlAPiBKcWJZZApKH6jYFst/yibIR239SSxByY9Y4ppTklCKMMobYDzSnLTAZKF6RWKMXGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Product ID" = _t, #"Item Name" = _t, #"Col#1" = _t, #"Col#2" = _t, #"Col#3" = _t, #"Col#4" = _t, #"Col#5" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Product ID", type text}, {"Item Name", type text}, {"Col#1", type text}, {"Col#2", type text}, {"Col#3", type text}, {"Col#4", type text}, {"Col#5", type text}}),
    #"Combine Columns" = List.RemoveFirstN(Table.ColumnNames(#"Changed Type"),2),
    #"Merged Columns" = Table.CombineColumns(#"Changed Type",#"Combine Columns",(colValues)=>let newColValues=List.RemoveItems(colValues,{"",null}) in Text.Middle(List.Accumulate(newColValues, "", (s, c) => s & "," & c),1) ,"Tag List")
in
    #"Merged Columns"