class Program
    {
        static void Main(string[] args)
        {
            var config = new Configuration().WithDefaultLoader();
            var document = BrowsingContext.New(config).OpenAsync(Url.Create("http://www.w3.org/TR/css3-background/#ltboxgt")).Result;
            Dictionary<string, string> atribute = new Dictionary<string, string>()
               {
                     {"Name","tr:nth-child(1) > td"},
                     {"Value ","tr:nth-child(2) > td"}
               };

            WriteAtributeToFile(document, atribute, "table.propdef tbody", @"D:\myOutput.csv");
        }

        private static void WriteAtributeToFile(IDocument document, Dictionary<string, string> atribute, string selector, string file)
        {
            using (var stream = new StreamWriter(file))
            {
                stream.WriteLine(string.Join(",", atribute.Select(a => a.Key)));
                foreach (var item in document.QuerySelectorAll(selector))
                {
                    foreach (var i in atribute.Select(a => a.Value))
                    {
                        stream.Write(item.QuerySelector(i).TextContent.Replace("\n", "").Replace(",", ""));
                        stream.Write(",");
                    }
                    stream.WriteLine();
                }
            }
        }
    }