The annual Literary Lights dinner, hosted by the Associates of the Boston Public Library, was a typically fancy affair the other night. The black-tie gala honoring writers and illustrators this year feted Julian Fellowes, the award-winning creator-writer-executive producer of the PBS hit “Downton Abbey,” who was also the evening’s featured speaker. Fellowes, joined at the ceremony by his wife, Emma , was presented with his award by “Masterpiece on PBS” executive producer Rebecca Eaton. The evening’s other honorees were journalist Jane Mayer, children’s author-illustrator Brian Selznick, “Call Me by Your Name” author André Aciman, and foreign correspondent Stephen Kinzer. Presenters included Stacy Schiff, Gregory Maguire, Alice Hoffman, and H.D.S. Greenway.