An associate professor is one step up from an assistant professor. The overall tasks between an assistant professor and associate professor are very similar with the difference that from an associate professor more initiative and proactivity is expected. You often have more academic freedom and job security as an associate professor, because you are expected to initiate and develop new research projects.
Key activities are: providing education, conducting research and doing administrative duties.
Overview of your tasks:
Scale 13 or 14 (Collective Labour Agreement of Dutch universities)