A ceiling grid lighting assembly for use in suspended ceiling systems is provided with multiple linear lighting modules in parallel arrangement. End plates are used to connect, support, and enclose longitudinal ends of the elongate body of each linear lighting modules while simultaneously functioning as reflective faces for optical cavities. A configured gap spacing between individual linear lighting modules can be used to house and support components such as additional light sources, acoustic or decorative panels, HVAC components, or power systems, controls or sensors. The end plate can also be configured to allow a T-bar to be placed in the configured gap spacing thereby enabling the mounting of the assembly in-line upon the longitudinal axis of a ceiling grid T-bar. Embodiments of linear lighting modules are presented comprising LED light sources, light guides and diffusers housed within the elongate body. The light guides may be edgelit from one or two sides and aligned horizontally or tilted relative to the ceiling grid plane.