The other important piece is space to move around. Some of your gamers will be big fellas. My old home store had three strip mall lots. A main store in the middle, a primary gaming hall on the right, and a gaming hall on the left that could have the doors locked and reconfigured so that you could only enter from the store area (Organized event area, reserved gaming space, boss's personal playground day, etc).
A rival store had a single strip mall lot. Their tables were ended end, chairs were almost back to back and they lined their walls with product. They had huge miniature gaming tables, two painting stalls and a large register. Where is the product? Hanging on wall racks that people bump into moving around the store. A minimal display was up near the register. On a full day people did not browse. They would walk in, look at the gamers and not want to have to inch past people to look at items. I will try to see if I can take pictures of my old home store and show you what the displays are like when I visit over christmas. Depending on what they've done since I left, they have three or four large aisles to walk up and down with lots of product to look at, most organized by theme and the more expensive, fragile, 'hot' items are located closer to the register.
Side note, if you have a large store and you run an event with 20+ people, you want to get a person to be your 'spotter'. You and your staff are busy with the register. You want someone watching product and shady customers at all times during large events. Make sure you trust this person. Your store is full of cool stuff and there are people who have no objection stealing your stuff. It will happen at some point. Prosecute them to the fullest extent of the law.