The rear axle's actual capacity is greater than the entire truck's payload limit, which is limited by GVWR based on other capacities, such as braking capacity. In the very LEAST, the rear axle can support OVER 1500 pounds in addition to the empty weight, as the Tacoma configuration with the greatest payload capacity has a capacity over 1500 pounds. 4x4's and V6's have lower payload capacities despite their added weight being over the FRONT axle because of the GVWR limitations.
Tacoma 4-cyl prerunner ~1500
Tacoma 4-cyl 4x4 or 6-cyl prerunner ~1400
Tacoma 6-cyl 4x4 ~1300
Now there is some logic to the added rear axle weight being greater than the actual weight. This is because the load is extended behind the rear axle, this weight is therefore not straight down on the axle, but prying UP on the front of the vehicle. Weight is being transferred from the front axle to the rear axle using the same principle with which a WD hitch transfers trailer weight from the hitch to the front axle of the truck. HOWEVER, Toyota did account for this when establishing the towing limits. Tacoma is designed to support a minimum of 650 pounds on the trailer hitch. Probably a bit less cantilevered out from the hitch like that, but within the safety margin.
Find your GVWR and just don't go over that and you'll be perfectly fine.
Edit: I don't see any mention of 4x4 in your profile, is yours a prerunner?
1430 payload cap - 500 hitch (the hitch capacity includes its own weight) = 930 pounds available for driver, passengers, fuel, and cargo.