An assembly comprising: a first frame defining a central component of a core of a tray table and comprising a first set of engagement features integrally formed in the first frame; a second frame defining a leftward component of the core of the tray table and comprising a second set of engagement features integrally formed in the second frame; and a third frame defining a rightward component of the core of the tray table and comprising a third set of engagement features integrally formed in the third frame; wherein the first set of engagement features is configured to engage the second set of engagement features and the third set of engagement features so that the first frame, the second frame, and the third frame connect together to form the core of the tray table; wherein the first set of engagement features is configurable among multiple alternative modes of engagement with the second set of engagement features and the third set of engagement features so as to form multiple alternative widths of the core of the tray table; and wherein the second frame and the third frame each comprise a respective frame comprising a sliding assembly comprising: a base integrally formed in the respective frame; a pair of projections (244, 245, 247) extending from the base and curved toward one another; and a shaft slidably (122, 222) received by the pair of projections (244, 245, 247) so as to facilitate sliding of the core of the tray table relative to the shaft (122, 222). a first frame defining a central component of a core of a tray table and comprising a first set of engagement features integrally formed in the first frame; a second frame defining a leftward component of the core of the tray table and comprising a second set of engagement features integrally formed in the second frame; and a third frame defining a rightward component of the core of the tray table and comprising a third set of engagement features integrally formed in the third frame; wherein the first set of engagement features is configured to engage the second set of engagement features and the third set of engagement features so that the first frame, the second frame, and the third frame connect together to form the core of the tray table; wherein the first set of engagement features is configurable among multiple alternative modes of engagement with the second set of engagement features and the third set of engagement features so as to form multiple alternative widths of the core of the tray table; and wherein the second frame and the third frame each comprise a respective frame comprising a sliding assembly comprising: a base integrally formed in the respective frame; a pair of projections (244, 245, 247) extending from the base and curved toward one another; and a shaft slidably (122, 222) received by the pair of projections (244, 245, 247) so as to facilitate sliding of the core of the tray table relative to the shaft (122, 222). a base integrally formed in the respective frame; a pair of projections (244, 245, 247) extending from the base and curved toward one another; and a shaft slidably (122, 222) received by the pair of projections (244, 245, 247) so as to facilitate sliding of the core of the tray table relative to the shaft (122, 222).