Create a relationship using a between two columns

In the query editor, you can define a custom column as a list:

{[#"From Entry No."]..[#"To Entry No."]}

 Remove unneeded columns and expand the list column.

 

Here's a full M query you can past into your Advanced Editor:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTIw1Dc00DcyMAJx3IsSMxJzFYLyk7OBPM8QIOGUWJKcYWAAkgVjU6VYnWglI5BOIySdwZm5+XkKTolgjcGJOanFCL0gxYZmQMLIDKzZGKTZGEmzV35GnoJLfnkqpl6QWiNzIGFsoBQbCwA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"No." = _t, #"Creation Date" = _t, #"User ID" = _t, Source = _t, #"Journal Batch Name" = _t, #"From Entry No." = _t, #"To Entry No." = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"No.", Int64.Type}, {"Creation Date", type date}, {"User ID", type text}, {"Source", type text}, {"Journal Batch Name", type text}, {"From Entry No.", Int64.Type}, {"To Entry No.", Int64.Type}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Entrie No.", each {[#"From Entry No."]..[#"To Entry No."]}, type list),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"No.", "From Entry No.", "To Entry No."}),
    #"Expanded Entrie No." = Table.ExpandListColumn(#"Removed Columns", "Entrie No."),
    #"Reordered Columns" = Table.ReorderColumns(#"Expanded Entrie No.",{"Entrie No.", "Creation Date", "User ID", "Source", "Journal Batch Name"})
in
    #"Reordered Columns"