Hi Rafael,
I am sorry to inform that I never heard about query manager in HANA.
Do you mean loading a query in SQL editor/console in HANA studio?
If yes, then before loading, first you need to save your SQL query.
After writing the query, right click on the query and select Save and give meaningful name and leave the type (*.sql).
Remember the path you are saving the file as it is required while opening this file.
Now this query is read to open in SQL editor/console.
Now instead of writing the query again, you can just place the query by right clicking anywhere and choose 'Open file'
Navigate to the path of file you saved and click on open.
Your query will now be seen in SQL editor.
Regards
Raj