Staggering bells is the first place to start. Instead of putting all the bells in a straight line, set the accidentals up to the far side of the table, so the bells look something like a piano keyboard. In this option the bells you use the most are closest to you. And the handles of the accidentals take up less space between the castings of the diatonics, so horizontal space is freed up. Consider also making your lines curved.
Bells are essentially wedge-shaped, wide at the outside and narrow at the inside.
If you arrange the bells with the same spacing between the handles as the castings, you'll end up with an arc of bells on the table. This frees up additional horizontal space PLUS it gets the handles closer together for those quick changes. This way the curve of the lines of bells can follow the angle of the table, while still leaving as many handles as possible as close to each other and the ringer as possible. The best thing to do is to get rid of bells you aren't using. Short of changing the physical properties of the bronze, the bells, or the room you're playing in, the best thing you can do to enhance the sound of the bass is to get the bells off the table.