Dennis, I am thinking the two points should be rounded over. The points will probably be weak if it is made of wood anyway and when the table is let down, they are snag points.
Just guessing here, but they look larger than 10". While I want function, I also don't want it to look like it is about to fly away at any moment. The smallest it can be and still provide function the better it will look. I don't see where anything larger than one standard plate diameter would be necessary (which is around 10"). That still leaves plenty of room for season shakers or pepper mills behind it or on the other side table.
For anyone new to the side table discussion, here is the original thread.
http://www.komodokamado.com/forum/viewtopic.php?t=199
-=Jasen=-