Palo will attempt to meet your request. They will not seat you with couples (it is assumed that couples want to dine alone). On my last cruise, I was at Palo twice. Once, I was a single seated alone. The serving staff made my night great! The second time, I called the day that I wanted the ressie and asked if there were any openings. I was told that I could come IF I was willing to share a table with "a nice lady" who had asked for a companion if possible (I'm female also, if that matters). So, that time, we dined together.
I'd do it again either way. Don't skip Palo just because you're single.