UITableView has a property backgroundView that can be used to set an UIImageView to display an image in the background of the table. In the below example we set the background property of UITableView to an image.
UIImageView *background =
[[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"back.png"]] autorelease];
theTableView.backgroundView = background;
This property was added in 3.2.0 release so check if iOS version >= 3.2.0 before using this.