Yes, and yes they will all dim together.
Since you only have one switch, you just need to replace it with a dimmer switch. The only thing to look at is the maximum wattage for the switch. Add up the wattage of each bulb (probably 65 each) and then buy a dimmer rated for at least that value. I'd probably get a dimmer with a slightly higher wattage rating.
There should be just two wires on the old switch, and they will just need to be removed from the switch and put on the dimmer. Generally, the dimmer will use small "wire nuts" to attach the wires (instead of screws like the switch has).
In use, note that the switch plate may become warm, but unless it is uncomfortably hot, you should be safe.
Here is a link to the procedure.
Best of luck,
WallyH