Can I export the lessons, teachers, subjects to MS Excel?

You can export the data you have inputted to MS Excel.

Choose menu File/Export/Export to MS Excel:

The following dialog appears. You can select what you want to be exported:

The most usefull is probably to export contracts. This export all the data into several sheets for each list. Please note that there are several sheets:

Notes:
- you can import these exports back to aSc TimeTables. Check this article Importing from Clipboard (MS Excel)