I'm a Performer owner and love it -- The gas starter built in is wonderful.
As to your table I think you'll need some sort of air gap between the kettle and the surface because a Weber kettle gets mighty hot during a cook. If you've got the kettle in direct contact with the wood, there will be char and, potentially, a fire.
Try cutting the hole for the kettle about 1/2 inch larger then use some metal fasteners like stainless steel wood screws driven in about every three or four inches around -- support the kettle rim on them, not wood.
This is just a guess. Maybe somebody will show up who has done this.