Wiktionary
n. A rigid structure to support electric cables; a type of raceway, normally having the appearance of a ladder and open at the top to facilitate changes.
Wikipedia
In the electrical wiring of buildings, a cable tray system is used to support insulated electric cables used for power distribution and communication. Cable trays are used as an alternative to open wiring or electrical conduit systems, and are commonly used for cable management in commercial and industrial construction. They are especially useful in situations where changes to a wiring system are anticipated, since new cables can be installed by laying them in the tray, instead of pulling them through a pipe.
Usage examples of "cable tray".
Almost directly above them, crawling carefully along the overhead cable tray, was Mordecai.