The Beam Weapons skill covers the usage and maintenance of standard coherent beam energy weapons such as lasers, particle beam weapons, plasma ri es, and microwave weapons (p. 338, EP).
A player uses their Beam Weapons skill whenever attacking with a beam weapon in combat (p. 191, EP). Beam Weapons may also be used for tests involving maintenance of the weapon, but not for repairing or modifying the weapon (that would be Hardware: Armorer skill).
Example (optional) specializations include Lasers, Microwave Weapons, Particle Beam Weapons, Plasma Rifles.