A tablet adjustment mechanism is provided to control the movement of a tablet of a seat assembly between a lowered non-use or stowed position under the armrest and a raised or use position, and further control the tablet's movement between an inward use position and an outward use position. The adjustment mechanism includes a plunger inside of a pivot element, the plunger's longitudinal and rotational or pivotal movements being controlled by a pin engaging a slot in the plunger, and also by a guide pin traversing an arcuate slot in a tablet support arm. The adjustment mechanism may limit lateral or sideward movement of the tablet when the tablet is in its fully lowered or stowed position and during at least some of the pivotal movement toward its raised position.