Annuals grow fast. Perennials are slower, they are in it for the long haul. Basil is nice. Sage is pretty, though will be very small the first year from seed. Calendula is always cheery. Echinacea is one of my favorites for visual appeal. It would just be a small plant this year but could possibly bloom next year. Lemon balm is doable from seed, would be small but always fragrant. Sorrel is possible but would have to be moved out of the pot sooner rather than later.

I'd avoid cilantro and dill - too fast and ill suited to pot-culture. Parsley isn't best for pots either. Thyme and lavender to slow and tiny from seed for your event. Chives would be too tiny as well.

FataMorgana

What about using cuttings instead? Mint or rosemary could be used and they only take a few weeks. Rosemary would smell fantastic.