Hi @Johannes,
This is on our roadmap: How can plugins add tables to /export-data? · Issue #112 · Pioreactor/pioreactorui · GitHub
Currently, you will have to use the utility:
pio run export_experiment_data --help
Example:
pio run export_experiment_data --tables my_custom_sql_table --output ~/output.zip
This puts a file output.zip into your home folder, and you can scp / filezilla it to your local computer.