To insert a more elaborate background you first need to add the tile, picture of your chosen background to a Photo Album.

To find out the URL, click on the picture in your photo abum so that it appears in it's own window, then right click. This will bring up a drop down menu, scroll down to PROPERTIES'  and highlight the URL Address. The URL of the above picure is

 

After highlighting you right click and copy.

 

Go back to your CREATE/EDIT TABLE and insert your cursor into the Background Image URL box, then press 'Ctrl' and 'v' simultaneously. You should see the URL address appear in the box.

NB: It can take a while to master this technique but please persevere. Also, may find that you add several v's to the address - vvvvhttp://groups.msn.com. . . . .. Don't worry, just delete these v's before continuing!

 

Example:

 

 

Here is your completed table.