Question: I want to set the border of a table to be "1px solid black" except on the bottom, where I want to use an image which provides a pointer into the link - as a visual aid.

Is it possible to set an image as the bottom border when the other borders are regular css.

Answer: 
I don't think so. You're probably better off adding a <DIV> below the table, give it a black border, a fixed background, and some fixed padding or whatnot (to give it some size).
No. Why don't you try another table row for that purpose?