As long as you have the url of an image file (i.e., ending with .jpg, .png, something like that), you should be able to get it to appear in the results of your table. You can look at the image insertion template the table description field gives you when you click on it, or you can follow my explanation below:
1. start with a bang: put an exclamation point (!)
2. then image description in brackets, no space between the brackets and the bang [like this for the desc]
3. then, in parens, the img url (likethis.png)
4. last, the image title, which user will see on mouse hover (this goes inside the parens, after the img url, in double quotes, (imgurl "like this")