How to create nested cells inside the same table TD

How to create nested cells inside the same table TD

I have the following table:-
<table class="table table-striped">
<thead>
<tr>
<th></th>
</tr>
</thead>
<tbody>
@foreach(var permisionMag in Model.PermisionManagement)
{
<tr>
<td >@permisionMag.Name</td>
@{int i = 0;
<td class="f">
@foreach (var item in permisionMag.TechnologyTypes.OrderBy(a =>
a.Name))
{
@(i+1) @item.Name
i = i + 1;
}
<br />
</td>
}
</tr>
}
</tbody>
</table>
but currently i need the second column to have nested rows instead of
showing the rows inside the same TD ? any advice on this ?