If your table is slanting after the assembly, there are 2 possibilities:
1) Different in height between legs 0,0 - 1,2 cm: Adjust the 4 feet underneath the leg.
2) Different in height between legs 1,3 - 3,0 cm:
The drive shaft between the legs has been turned half a round too much in the right side of the table. Disassemble the table and and turn the drive shaft half a round so that the table is straight. Any remaining slanting can be adjusted by the feet underneath the leg. Read the assembly instruction in the process.