How to distribute lessons in multiple weeks timetable.

You can do so via advanced card relationships "Max days per all weeks".
Let's take a case, when you have 15 English lessons and you wish to distribute them into 8 days in 3 weeks timetable.
Just set this advanced relation:

Note: You can also limit gaps in a day for selected subject, or set another relations to specify max days per one week only then you can get this result: