A horizontal stabilizer or tailplane does two things, usually - it makes the aircraft aerodynamically stable in pitch for the desired range of centres of gravity, and it provides a means to create variable pitching moment for aerodynamic control of the aircraft angle of attack.Thus it provides both "stability" and "control"
The former goal (stability) may be achieved instead by means of locating the centre of gravity relative to the wing (or vice versa) in such a fashion as to provide the required stability. Detail shaping of the wing in a spanwise sense may also help for a swept wing aircraft.
The latter (control) can be achieved by means of using trailing edge devices on the wing to create changing pitching moments for the same purpose of adjusting angle of attack.
Both are less efficient ways to achieve the specific goals, but if there are other compelling reasons to use the delta planform then these disadvantages may be acceptable to the overall design.