Patrons eating at Koi Japanese restaurant in Los Angeles Thursday night were treated to a surprise floor show: A nasty altercation between Sharon Osbourne and an ICM agent named after a diet soft drink. Osbourne and Renee Tab — who have been feuding since January over whether Tab belonged at an Osbourne party where she won a $15,000 necklace — allegedly got into a brawl that landed Ozzy's more eccentric half in the emergency room. Sharon's rep says her client was "viciously assaulted," while Tab's attorney claims Sharon "started with spitting on her and calling her names." A police investigation is underway. Early word is that both ladies will be charged with acting like 12-year-old girls.