using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

​

    public static void Main()

    {

        string value = "mrgar@yahoo.com; mrgio@yahoo.com; mrrame@gmail.com";

​

        var values = value.Split(';', StringSplitOptions.RemoveEmptyEntries);

        string Table1 = values.First();

        string Table2 = string.Join(';', values.Skip(1)).Trim();

​

        Console.WriteLine(Table1);

        Console.WriteLine(Table2);

    }

}