how to Deserialize a JSON string and copy to two different datatables

Check this by using Newtonsoft.Json library.

var jsonData = JsonConvert.DeserializeObject(your_json_data);

// Create DataTable for ID, Name, and Description
DataTable mainTable = new DataTable();
mainTable.Columns.Add("ID");
mainTable.Columns.Add("Name");
mainTable.Columns.Add("Description");

// Create DataTable for Distributors
DataTable distributorTable = new DataTable();
distributorTable.Columns.Add("ID");
distributorTable.Columns.Add("DName");
distributorTable.Columns.Add("LastName");
distributorTable.Columns.Add("Email");

foreach (var item in jsonData)
{
    DataRow mainRow = mainTable.NewRow();
    mainRow["ID"] = item["Id"].ToString();
    mainRow["Name"] = item["Name"].ToString();
    mainRow["Description"] = item["Description"].ToString();
    mainTable.Rows.Add(mainRow);

    foreach (var distributor in item["Distributors"])
    {
        DataRow distributorRow = distributorTable.NewRow();
        distributorRow["ID"] = item["Id"].ToString();
        distributorRow["DName"] = distributor["DName"].ToString();
        distributorRow["LastName"] = distributor["LastName"].ToString();
        distributorRow["Email"] = distributor["Email"].ToString();
        distributorTable.Rows.Add(distributorRow);
    }
}

Console.WriteLine("Main Table:");
foreach (DataRow row in mainTable.Rows)
{
    Console.WriteLine($"{row["ID"]}, {row["Name"]}, {row["Description"]}");
}

Console.WriteLine("\nDistributor Table:");
foreach (DataRow row in distributorTable.Rows)
{
    Console.WriteLine($"{row["ID"]}, {row["DName"]}, {row["LastName"]}, {row["Email"]}");
}