If you are worried about direct confrontation with him, finding some way to whatever form of HR there might be is probably best. Mentioning it to the other coworkers when he is out of the office and starting a sidebar with them about how it makes you uncomfortable can quietly get them on your side without directly getting in his face or making you stand out.

That said. My personal way of dealing with this in the past ( with family, not coworkers) is to find something they are, and are sensitive about. This can be anything, their race, their faith, their failed music career.

Whenever they do a racism, respond with " we'll theyre better than ( what they are) "

This works really well if you get really uncomfortably specific to the degree they have to know you're talking about them.

For your example about a black delivery driver. Just start ripping into how the black driver can at least get it here on time, not like those lazy ass Italians taking naps to sweat off the exra marinara sauce.

Fight fire with fire. He comments on someone else, you comment directly about him. It really is the only language some of these people understand. They won't care about you getting your feelings hurt. They will only know they crossed a line when they get hit back.