I am dynamically adding data to a cell with the following code:
for(int i = 0; i < matchedSlots.size(); i++)
{
String title = matchedSlots.get(i).getTitle
ImageIcon image = new ImageIcon("image.gif");
...
tm.addRow(new Object[] {image,title,director,rating,runTime});
You may need to change your table model to account for the new column if you haven't already.
This short article should help you with the image renderer: http://mdsaputra.wordpress.com/2011/06/13/swing-hack-show-image-in-jtable/