What do most of the jobs done on spacewalks consist of? Changing small pieces on the ISS? Unbolting/unplugging a piece and putting the new one in?
You can read a brief summary of every ISS EVA ever (there have been almost 200 of them) at this wikipedia page.
If I were to attempt to summarize, there would be a few common categories.
- Connecting cables and wires
- Mounting devices such as antennae, Orbital Replacement Units (pumps, relay boxes, etc), cameras, et al
- Working with the robotic arms to attach large elements to the station with bolts and remove their launch restraints
- Various remove-and-replace repair jobs (including greasing bearings)