The Import Export Powertool could be used to import this information, but it’s not a practical way to use it. To properly update Inventory Counts in Business Central, you would want to use the built in counting tools that Business Central offers such as the Physical Inventory Journal. Once you dive into counting lot numbers and serial numbers, I’d highly advise against using the Import Export Powertool.
Your best approach to handle this is to use the Physical Inventory Journal. Since you are very new to Business Central, I would strongly encourage you to talk to your Business Central partner/consultant on this.
I also encourage you to look at our Advanced Inventory Count solution. While it’s not free, it’s meant to make counting in Business Central more flexible and easier. You could perhaps use it in tandem with the Import Export Powertool.