First of all, my table would be circular, not rectangular. I think King Arthur was right on the money in this regard. From a practical matter the rectangular table can obscure your view of some of the people sometimes. And it's easier to trick the players into thinking they're your equal if you're not at the head of the table. But seriously, I'm one of those old-fashioned DM's of the Judge Dredd school ("I am the law!") but I also believe that everyone at the table deserves the same courtesy and consideration. A round table de-emphasizes the DM-player power relationship in favor of a more egalitarian mood.
Also, the tabletop would totally have this totally rad magickal okkult symbol on it:
There'd be a chair at each corner of this unicursal septagram, for seven spaces at the game table. Six players is pretty close to an ideal for me. Three or fewer players feels inadequate, like I'm running half a game. Four or five feels like a full table. Six is where it really gets interesting, because at six players it's usually clear that I don't have any real ability to predict what the group is going to do. At that size of a group I'm slightly out of my league and have to work a lot harder.
To me one of the best parts of DMing is that you get a chance to build all sorts of fun static pieces like monsters, dungeons, wilderness environs and then you let players loose on them to see what happens. Usually it involves watching your toys getting broken, but hopefully the players do an interesting job of wrecking your precious creations. A few more players than you can safely handle adds a little extra frisson.
Also, I just like the idea of having a game table with a spooky-looking symbol on the table.
Another element of my gaming table goes back to my ridiculous pet theory on the origin and relevance of RPGs. It might have been over at the Forge where I first heard it explicitly claimed that role-playing taps into the storytelling circuit of the brain that's been present in humanity since cavemen sat around bullshitting about the giant mammoths that got away.
I don't dig on the notions of "storytelling" and "narrativism" in terms of RPG theory and design, but I think there's some truth to this premise. And that's why when playing a game that did not require a board or display, I'd put some fire in the center of the table. Sitting around staring into the fire and chewing the fat is becoming something of a lost art in modern technological societies. Instead we either sit in front of the TV and let it do all the talking or hang out together someplace without the soothing benefits of watching the flames dance.
Now, I know that if I put a candle or something like that in the center of the table every single session I'd eventually set something on fire, like a charsheet or my sleeve. To avoid that possibility I'd use a substitute that happens to be one of the greatest inventions of all time:
Lava lamps are pure distilled awesome. I never did drugs in college. I didn't need them to enter interesting altered states as staring at my lava lamp achieved the same effect on the cheap and without any biological side effects. But even if you aren't as susceptible to lamp-induced hypnosis as I am, the lava lamp produces intricate patterns of light in much the same way as a crackling fire. Think of the lava lamp as updated game equipment the way modern plastic polyhedrons are updates of dice carved out of bones.
So there you have it. My ideal gaming table: circular, with a strange seven sided star on the surface and a lava lamp in the middle.