Prevent the page from being displayed only when all the elements of the page are loaded

I have a page in html, in that ready data, this part looks like this:

        <table class="table table-responsive">
            <thead>
                <tr>
                    <th>Item 1</th>
                    <th>item 2</th>
                    <th>item 3</th>
                    <th>item 4</th>
                </tr>
            </thead>

            <tbody>
                {% for item in itens %}
                <tr>
                    <td><a href=""><img src="{{ item.att1 }}" width="50px" /></a></td>
                    <td><a href=""><strong>{{ item.att2 }}</strong></a></td>
                    <td><strong>{{ item.att3 }}</strong></td>
                    <td><strong style="color: green">{{ item.att4 }}</strong></td>
                </tr>
                {% endfor %}
            </tbody>
        </table>

I'm using Django in my application.

The problem is this: the data being listed is captured on the backend and comes from an external server, which often delays loading of the page.

What I wanted to do was load the whole page (except the table), and meanwhile I could put any message to the user. And only then when all items were loaded, would the table be displayed.

I've been researching but I have not found anything related. Could someone help me?