In your table view controller override the GetCell function, this is typically a required step if you want to display data. Now you must create your own AccessoryView, this can be a complicated view, but for now let’s start with the most basic form;
UIView cellView = new UIView(accessoryRectangle);
cellView.BackgroundColor = new UIColor(0f,1f,0f,1f);
cell.AccessoryView = cellView;
so we now have a lovely green square, very professional. To prove you can use other assets, and to do something slighlty more useful, just use a label;
label.Text = ">";
cell.AccessoryView = label;
there you go, hopefully you can see that you could create as complicated a view as you want.