Expanding list within column

Try this rmahmood 
It uses Value.Is to determine if it is a list or not, then extracts the numbers. From there you can split columns, or whatever.

let
    Source = #table(
                {"ID", "Name", "City", "Other"},
                    {
                        {123, "Alice", "Wonderand", ""},
                        {456, "Bob", "Wonderland", {1..10}}
                    }
            ),
    #"Added Custom" = 
        Table.AddColumn(
            Source, 
            "Custom", 
            each 
                if Value.Is([Other], type list) 
                then Text.Combine(List.Transform([Other], Text.From), ",")
                else [Other]
        )
in
    #"Added Custom"

How to use M code provided in a blank query:
1) In Power Query, select New Source, then Blank Query
2) On the Home ribbon, select "Advanced Editor" button
3) Remove everything you see, then paste the M code I've given you in that box.
4) Press Done
5) See this article if you need help using this M code in your model.