MemoryTarget = new MemoryTarget();

        CsvLayout csvLayout = new CsvLayout() { Delimiter = CsvColumnDelimiterMode.Comma, WithHeader = true };

        csvLayout.Columns.Add(new CsvColumn() { Name = "Name", Layout = "${event-context:item=Name}" });
        csvLayout.Columns.Add(new CsvColumn() { Name = "AuditTimeStamp", Layout = "${event-context:item=AuditTimeStamp}" });

        MemoryTarget.Layout = csvLayout;

MemoryTarget.Logs

string header = ((CsvLayout)MemoryTarget.Layout).Header
    .Render(LogEventInfo.CreateNullEvent());