using System;

using System.Text.Json;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"{

            ""RandonName"": [

              {

                ""RandomKey1"": ""Data"",

                ""RandomKey2"": ""Data"",

                ""RandomKey3"": ""Data"",

                ""RandomKey4"": ""Data"",

                ""RandomKey5"": ""Data""

​

              },

              {

                ""RandomKey1"": ""Data"",

                ""RandomKey2"": ""Data"",

                ""RandomKey3"": ""Data"",

                ""RandomKey4"": ""Data"",

                ""RandomKey5"": ""Data""

​

              }

            ]

        }";

        Dictionary<string, List<Dictionary<string, string>>> dictonary = JsonSerializer.Deserialize<Dictionary<string, List<Dictionary<string, string>>>>(json);

        foreach (KeyValuePair<string, string> kvp in dictonary["RandonName"][0])

        {

            Console.WriteLine(kvp.Key);

            Console.WriteLine(kvp.Value);

            Console.WriteLine();

        }

        Console.WriteLine((String.Join(",", dictonary["RandonName"].SelectMany(x => x.Keys).ToList())));

    }

}