Razor Pages .net 2.0 expanding menu in table

I am new to Razor Pages and web development in general. I currently have a table which is displaying a model.

<table class="table"><thead><tr><th></th><th>
				@Html.DisplayNameFor(model => model.HighLevel[0].Item)</th><th>
				@Html.DisplayNameFor(model => model.HighLevel[0].ItemDescription)</th></tr></thead><tbody>
		@foreach (var item in Model.HighLevel)
		{<tr><td>
				@Html.DisplayFor(modelItem => item.Item)</td><td>
				@Html.DisplayFor(modelItem => item.ItemDescription)</td></tr>
		}</tbody></table>

this works fine for displaying some aggregated data I'd have. The functionality I'd like to provide though would be to click a row and have some child elements appear such as:

http://jsfiddle.net/zGRSF/

the child elements would come from another model that would be queried using linq based on data within the top level. I have the models complete but need some direction on how to interface that with the UI.