Yes, there are certain limits in O&D:
Excel sheets with over 500 columns may exceed the 15-minute time out. Please refer to this article for a workaround.
Turnsheets will slow down at around 5,000 cells. Using many formulas in your turnsheet will also make it slower. The performance impact will depend on the specs of your computer.
You cannot create more than 5000 documents at one time.