How to transform Spec-flow table data into different values

As Sam pointed out, we can use StepArgumentTransformarion or an approach similar to below. Add if else inside the extension methods if you want to map Value1 to Code1 for one type and Value1 to CodeX in another type using typeof(T).Name.Equals(typeof(yourtype).Name) as the condition

 public static IEnumerable<T> CreateSetWithValueTransfer<T>(this Table table)
    {
        var mapper = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase)
        {
            {"Value1", "Code1"},
            {"value2", "Code2"}
        };

        var set = ChangeValues(table, mapper);
        return set.CreateSet<T>();
    }


    private static Table ChangeValues(Table table, Dictionary<string, string> mapper)
    {
        var mappedTable = new Table(table.Header.ToArray());
        foreach (var row in table.Rows)
        {
            mappedTable.AddRow(row.Values.Select(x => mapper.ContainsKey(x) ? mapper[x] : x).ToArray());
        }
        return mappedTable;
    }