Driving multiple loads with a single TRIAC and multiple optoisolators
You can switch that one triac with multiple optos. The leakage current will be multipled by the number of optos so you might want to adjust R3 downward to compensate (read the datasheets and calculate the worst case gate current leakage at maximum opto temperature). 

The triac will turn on when any one of the optos is 'on', so it's kind of a power 'OR' gate. 

The one triac can switch multiple loads in parallel with each other, all on and off at the same time, of course. 

It's probably better to combine the signals on the LED side of one optoisolator unless you have some motivation for isolating those signals from each other. A simple 74HC NOR gate will work well if the signals share the same power supplies.