public class AccountViewModel
{
    ...
    public IQueryable<User> user { get; set; }
}

public class UserController : Controller
{
    private REc db = new REc();

    // GET: /User/
    public ActionResult Index()
    {
        AccountViewModel avm = new AccountViewModel();
        var users = db.Users.Include(u => u.USERROLE);
        avm.user = users;
        return View((avm.user).ToList());
    }

@model IEnumerable<SNAPAPP.Models.ViewModel.AccountViewModel>

@{
    ViewBag.Title = "Index";
}
    <table class="table">
    <tr>

        <th>
            @Html.DisplayNameFor(model => model.USERROLE)
        </th>
        <th></th>
    </tr>

@foreach (var item in Model) {
    <tr>

        <td>
            @Html.DisplayFor(modelItem => item.USERROLE)
        </td>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id=item.ID }) |
            @Html.ActionLink("Details", "Details", new { id=item.ID }) |
            @Html.ActionLink("Delete", "Delete", new { id=item.ID })
        </td>
    </tr>
}

</table>

var users = db.Users.Select(x=>new AccountViewModel { Id=x.Id}).ToList();
return View(users);