Determining maximum current through 18 gauge wire in robot arm

For a robotics application, I'd like to power some external electronics and sensors off the logic circuit in a robot arm.

The components are a computer (19V, 65W => 5A), 2 cameras (1.2A), 1 light (0.35A), USB2.0 I/O board, and power board. All this on top of current draw from the motor logic, which runs off a 4.3A power supply atm. Therefore, I estimate the upper bound to be 12A.

The logic power runs through an 18 gauge wire. According to this table, 18 gauge permits either 16A as chassis wiring, or 2.3A as power transmission.

Note the robot arm is roughly 0.6m long; obviously, because the logic power runs internally, the wire length is greater than 0.6m.

Will I be able to power my electronics from logic power?

I am willing to test my system empirically.

(BTW, as a CS major, I have zero experience with electronics.)