Abstract: Detachable bottle and food holding subtrays and clamps for attaching onto the raised ridge edges on trays used in highchairs, strollers, booster chairs, and activity chairs. The clamps can be a single component having a curved upper flange for fitting about the raised ridge of the existing tray, and an upper bent flange having an end which abuts against a lower surface of the tray. Dual cylindrical bottle subtray holders and flat planar food subtray holders can snap onto the clamp leaving the bottles and food in the subtrays at a lower level than that of the tray out of reach of a sitting child. Another clamp has a general C-shape with either a screwable post or spring biased post locking the clamp to the raised edge of the existing tray. Another clamp has plural clip portions for attaching the subtray holders.