async + memory leak kind of issue

Program.cs

class Program
{
    private const int MegaByte = 1048576;

    public static void Main(string[] args)
    {
        Console.WriteLine("Process ID: " + Process.GetCurrentProcess().Id);

        var tasks = new List<Task>();
        for (var i = 0; i < 10; i++)
        {
            tasks.Add(Task.Run(RunAndBlock));
        }

        Thread.Sleep(TimeSpan.FromSeconds(10));

        while (true)
        {
            Console.WriteLine("Working set: " + Process.GetCurrentProcess().WorkingSet64 / MegaByte + " MB");
            Console.ReadLine();
            GC.Collect();
        }
    }

    static async Task RunAndBlock()
    {
        Console.WriteLine($"Started task");
        await DoWork();
        GC.Collect();
        Thread.Sleep(TimeSpan.FromDays(1));
    }

    static async Task DoWork()
    {
        var data = AllocateMb(100);
        await Task.Yield();
        Console.WriteLine($"Allocated {data.Length / 100} MB");
    }

    static object[] AllocateMb(int mb)
    {
        var data = new object[mb * 100];
        for (var i = 0; i < data.Length; i++)
        {
            data[i] = Allocate10Kb();
        }

        return data;
    }

    static byte[] Allocate10Kb()
    {
        var random = new Random();

        var data = new byte[10240];
        random.NextBytes(data);

        return data;
    }
}