public class ShoppingListModel
{
    public string Name { get; set; }
    public List<ItemModel> Items{ get; set; }

    public ShoppingListModel()
    {
        Items=new List<ItemModel>();
    }
}

ShoppingListModel = function(data) {
    var vm = ko.mapping.fromJSON(data);
    return vm;
};

@{
    var jsonSerializerSettings = new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() };
    var data = new JavaScriptSerializer().Serialize(JsonConvert.SerializeObject(Model, jsonSerializerSettings));
}

@section scripts {
<script src="~/App/ShoppingListModel.js"></script>

    <script>
        var vm = ShoppingListModel(@Html.Raw(data));
        ko.applyBindings(vm);
    </script>
}

@Html.HiddenFor(model => model.Name, new { @data_bind="value:name"})
<input type="text" data-bind="value:name"/>

@Html.HiddenFor(model => model.Items, new { data_bind = "value: items" })

<tbody data-bind="foreach:items">
    <tr>
        <td>

            <span data-bind="text:name"></span>
        </td>
        <td><span data-bind="text:count"></span></td>
        <td>
            <button class="btn btn-xs" data-bind="click:$parent.remove">
                <i class="fa fa-trash"></i>
            </button>
        </td>
    </tr>
</tbody>

<input type="hidden" value="xxx" />

vm.itemsJson = ko.computed(function() {
    return ko.toJSON(vm.items);
},this);

<input name="itemsjson" type="hidden" data-bind="value:itemsJson"/>

public List<ItemModel> Items{ get; set; }

public string ItemsJson { get; set; }

var items=JArray.Parse(model.ItemsJson);

model.Items = items.
    Select(i => new ItemModel {Name = (string) i["name"], Count = (int) i["count"]})
    .ToList();
return View(model);

function YourViewModel() {
     var self = this;
     self.items = ko.observableArray(); //fill it with your stuff;
     self.valueForHiddenField = ko.computed(function() {
         return ko.toJSON(self.items);
     }, this); //use this observable as value of your hidden field
}

<form>
   <!-- ko foreach: items -->
       <input type="hidden" data-bind="value: property1, attr: { name: 'Items[' + $index() + '].Property1' }">
        <input type="hidden" data-bind="value: property2, attr: { name: 'Items[' + $index() + '].Property2' }">
   <!-- /ko -->

</form>