The table fans are designed for your requirements. There is no change in the performance if you are planning to place it on the table or mounting it on a wall. But let us understand the aerodynamics. If you place the fan at a certain height and if it has external air influence, the motor may take more power to offer the same high speed. This may result in fans making some noise or the air may not be circulated evenly. You can also observe the same with the ceiling fans. The performance of your fan depends on the place where you have planned to keep it too.