Moving and manipulation 

The whole model is easy to move/rotate by selecting either the "table_lamp1" group or the "base01" object, which is the root parent.
"AC01" object can be moved independently.
The lamp's arms are easy to manipulate by by rotating "arm01" and "arm04" objects along their local Z axes and "arm_base" along its local X axis - all involved objects have appropriate constraints and will adjust automatically.
The "arm_base" object can also be rotated by 90 degrees along its local Z axis to change the way the lamp is mounted to the surface (table or wall mounting). With wall mounting, "base02", "base03", "base_knob" and "base_nut" objects should be hidden or removed.
The lamp can be adjusted in several planes by rotating the "arm07" object along its local Y axis, "arm08" along its local X axis and "lamp01" along its local Z axis. 

Materials 

The "emit" material (assigned to "lamp08_emission" object) emits light with colour based on the blackbody temperature, default value is set to 3500K. 

Additional objects 

Most of empty helper objects are necessary for proper lamp manipulation and shouldn't be deleted.