example.cs

void Main()
{
	var s = new StringBuilder();
	s.AppendLine("Id,Name,A,B,C");
	s.AppendLine("1,one,9,8,7");
	s.AppendLine("2,two,6,5,4");
	using (var reader = new StringReader(s.ToString()))
	using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
	{
		csv.Configuration.RegisterClassMap<FooMap>();
		csv.GetRecords<Foo>().ToList().Dump();
	}
}

public class Foo
{
	public int Id { get; set; }
	public string Name { get; set; }
	public DateTime? Optional { get; set; }
	public Dictionary<string, int> TheRest { get; set; }
}

public class FooMap : ClassMap<Foo>
{
	public FooMap()
	{
		Map(m => m.Id);
		Map(m => m.Name);
		Map(m => m.Optional).Optional();
		Map(m => m.TheRest).Index(2);
	}
}