Even before Cloudlog was forked into Wavelog, the advanced search function already supported exporting results to CSV files.
For example, my Cloudlog is still running on an older version from several years ago, and I can export data in CSV format. I use this to generate the reports required for annual inspections each year. As long as I set up some rules (either "always match" or "never match"), it will work.
https://log.bh5hsu.com/index.php/search/filter
Additionally, if you have database access, you can use a database management tool to directly export tables to CSV/Excel files.