A workshop was a room where items were constructed and planned.
The Master of Tarquin Hill had a workshop on planet Kurl, where he produced ceramic objects 300 years ahead of his time. (TNG: "The Chase")
Leonardo da Vinci had his own workshop in 16th century Florence, which was recreated in a holoprogram by Kathryn Janeway in the 2370s. (VOY: "Scorpion", "Concerning Flight")
Section 31 Headquarters included multiple workshops, including an east workshop and a west workshop. (DIS: "Project Daedalus")
In 2268, one of the Alice series androids assured James T. Kirk that the planet Mudd's research laboratories and workshops were "extremely well equipped." She and another Alice added that the crew of the USS Enterprise was free to visit them. Kirk replied that they might do so later. (TOS: "I, Mudd")
When Miles O'Brien planned to build an arboretum for his wife in 2371, essentially turning her botany profession into a hobby, Julian Bashir rhetorically asked him whether he would be satisfied with sitting in a workshop building nano-circuit boards and playing with tricorders instead of working as an engineer. (DS9: "The House of Quark")
The next year, Miles set up a workshop in the bedroom of his family's quarters, which didn't meet the approval of Keiko. (DS9: "Hippocratic Oath")
In 2373, Captain Sisko convinced Garak to go on a mission to Empok Nor by helping him procure more space for the workshop of Garak's Clothiers. (DS9: "Empok Nor")