Hi Linda,
My table actually has two tops, the other one is a cutting board. We made it so that that one could store underneath the other one. When I want to press large items, the press board is up. Most of the time the cutting mat is on top. The trim is made out of natural birch 1x2s to match the birch cabinet. Trim boards were attached at just the right height so that they are flush at the top when both pieces are there, doesn't matter which is on top. The pressing board has a very small 45° angle cut out of one corner (finger size) so that I can pull up on it to move it. The trim board ends were cut at a 45° angle to eliminate sharp corners.
Cutting Mat Top:
http://www.flickr.com/photos/athomesewing/3972406256/