Is it permissible to pray on a table 80 cm high that can only accommodate one person, while a clean spot is available on the ground?

There is no harm in praying on a table or a bed as long as it is stable on the ground. The well-known disagreement is concerning prayer on something that is being carried. Ibn Arafah mentioned that prostration should be on the ground or on something connected to it, like a "bed." Al-Tawdih stated that praying on a bed is permissible without disagreement. As for praying on a riding animal, if the animal is standing still and facing the Qiblah, with all pillars of prayer fulfilled, there are two views regarding the validity of the obligatory prayer, the more correct of which is its validity. However, if the animal is moving, the correct of the two opinions is that prayer on it is not valid, because it is not considered a stable place. Therefore, there is no harm in the prayer of those mentioned on a table that is fixed to the ground, as long as they are able to perform the prayer on it as Allah has commanded.