IF you have medical evidence (e.g. a report from a doctor) supporting that you have a *specific* diagnosable medical condition which is made worse by or exacerbated by working at a low table and that you need, for medical reasons, a desk, then the employer would most likely have to accommodate you. But in the absence of a medical diagnosis of a condition and a doctor's recommendation that you need a certain accommodation (and that accommodation is, as this one would seem to be, is reasonable), the employer can make your phsyical working conditions whatever it wants.