ID,Type,Name,Description,Image
11,Variation,MyCoolProduct,A super cool product, Image1 | Image2

var records = new List<Columns>
            {
                new Columns {ID = 12, Type = "Variation", Description = "Simple product with different colors",
                    Images = "Image1 | Image 2", Price = 19.99d}
            };

            using (StreamWriter sw = new StreamWriter("Testfile.csv"))
            {
                var writer = new CsvWriter(sw);
                writer.WriteRecords(records);
            }

public class ColMap : CsvClassMap<Column>
   {
       public ColMap()
       {
           Map(m=>m.ID).Name("ID").Index(0);
           .
           .
           .
       }
    }