$(document).ready(function () {
            update();
        $(".quant").change(function() {

            update();
         });
        function update() {

            var id = $('.quant').attr('data-id');
            var sum = 0.0;
            var quantity;
            $('#myTable > tbody  > tr').each(function () {


                quantity = $(this).find('.quant').val();
                var price = parseFloat($(this).find('.price').attr('data-price').replace(',', '.'));
                var amount = (quantity * price);

                sum += amount;
                $(this).find('.amount').text('' + amount + ' грн');

            });

            $('.total').text(sum + ' грн');

            $.get(
             '/Cart/AddTocart',
             {
                 id: id,
                 returnUrl: '',
                 quantity: quantity

             }
         );
        }

        });

var id = $(this).attr('data-id');

var quantity;
      $('#myTable > tbody  > tr').each(function () {
         quantity = $(this).find('.quant').val();
         ...
}

<thead>
    <tr>
        <th class="text-center">Товар</th>
        <th class="text-center">К-сть</th>
        <th>Назва Товару</th>
        <th class="text-right">Ціна</th>
        <th class="text-right">Загальна ціна</th>
    </tr>
</thead>

<tbody>
    @foreach (var line in Model.Cart.Lines)
    {


        IEnumerable<FurnitureImages> images = line.Furniture.Images;
        FurnitureImages mainImage = images.Where(x => x.IsMainImage).FirstOrDefault();

        <tr>
           <td class="text-center">
               @if (mainImage != null)
               {

                   <img src="@Url.Content(mainImage.Path)" style="width:110px; height:70px" />
               }

           </td>

            <td class="text-center">
            <input type="text" data-id="@line.Furniture.FurnitureId" data-price="@line.Furniture.Price" value="@line.Quantity" class="quant" />
            </td>
            <td class="text-left">@line.Furniture.Name</td>
            <td class="text-right price"  data-price="@line.Furniture.Price">@((line.Furniture.Price).ToString("#.## грн"))</td>
            <td class="text-right amount">@((line.Quantity * line.Furniture.Price).ToString("#.## грн"))</td>
            <td>
                @using (Html.BeginForm("RemoveFromCart", "Cart", new { Id = line.Furniture.FurnitureId }))
                {
                    @Html.Hidden("Id", line.Furniture.FurnitureId)
                    @Html.HiddenFor(x => x.ReturnUrl)
                    <input class="btn btn-sm btn-warning" type="submit" value="Видалити з кошику" />
                }


            </td>


        </tr>
    }

</tbody>

<tfoot>

    <tr>
        <td colspan="4" class="text-right"><b>Всього до оплати:</b></td>
        <td id="test" class="text-right total">@Model.Cart.ComputeTotalValue().ToString("#.## грн")</td>
    </tr>


</tfoot>