It is tough to use pepper spray in close quarters like that; you’ll get a lot of innocent diners, and probably yourself.
Here in NJ people have dedicated a lot of effort to avoid being in this position. Private schools, private pool clubs, private clubs for bars, anything that would make this encounter a matter of trespassing for the local police to deal with. A lot of non-Southerners are coming to understand segregation as they never thought they would.
Not all pepper spray formulations are the same. Some a more of a stream-type shot, rather than a more aerosolized-type shot. Cuts down on overspray.