@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Categ)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Txt)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Price)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Unit)
        </td>
        <td>
           Сюда нужно вывести количество @ViewBag.sm/item.Price
        </td>
     </tr>