Another option is to set table wrapping to Around in the Table Properties
dialog box. Then click the Positioning button, and set the Horizontal
Position: to Left. Under Distance from surrounding text, set the Bottom:
distance as desired. To make sure that no text sneaks in to the right
(assuming this is what you want), set the Right: distance to some
unreasonable amount such that no text would actually fit to the right
(assuming 1" margins for 8.5" paper size, setting Right: to 6.5" should
guarantee this).

After setting up a table shell this way, you can save it as an AutoText (or
Quick Part if Word 2007) for future use. I would do this if going Jean-Guy's
route, as well.