displaying None instead of data in the form of table

try this

<form action="{% url 'save_machine' %}" method="post">
    {% csrf_token %}
       <label for="machinename">Select Machine Name:</label>
       <select name="machinename" id="machinename">
           
           {% for machine in machines %}
           <option value="{{ machine.machine_name }}">{{ machine.machine_name }}</option>
           {% endfor %}
       </select>
       <br>
       <br>
       <label for="operationname">Select Operation Number:</label>
       <select id="operationname" name="operationname">
           
           {% for machine in machines %}
           <option value="{{ machine.operation_no }}">{{ machine.operation_no }}</option>
           {% endfor %}
           </select>
       <br>
       <br>
       <br>
       <input type="submit" value="Save">
   </form>

<tr>
    {% for choice in choiced_machine %}
    <td>{{choice.machine_name}}</td>
    <td>{{choice.operation_no}}</td>
     {% endfor %}
</tr>

change your view like this.

def save_machine(request):
   if request.method == "POST":
      machine_name = request.POST.get('machinename', '')
      operation_no = request.POST.get('operationname','')
      choiced_machine = Machine.objects.filter(machine_name=machine_name, operation_no=operation_no)
      machines = Machine.objects.all()
      return render(request,'usermaster/upload.html',{'machines':machines,'choiced_machine':choiced_machine})