Can Multiple People Inventory at the Same Time?

Yes, that's absolutely possible. Multiple people can be logged into the same organization at the same time, both in the web app and the mobile app. 

One tip is to divide the inventory task into different categories, for example, one person inventories all the chairs, another inventories all the tables, etc. By doing this, you can avoid double inventorying of models, and it becomes easier to recognize what you've inventoried in your model library.