Jill Kargman is a pleasant singer. Her voice is lovely, in fact, but that is not why audiences joined her inside the legendary Caf Carlyle for a string of sold-out performances which began on January 17. No, patrons made their way to the Upper East Side venue on this damp winter evening to hear Kargman’s hilarious and often cringe-inducing war stories from her New York City upbringing, through her entrance into show business and Manhattan motherhood.