I want to find out if it is possible to upload price or items into manager using excel file.
You can export the format of any module like customers, inventory items, etc. using the batch create option available at the bottom of every screen when you open a module. Then just follow the instruction to copy what is shown in your screen and paste in excel. you can update the details in excel and then later import it by copying the data back from excel and pasting the same in the space provided and clicking next and update.
Yes, click on the Inventory Items tab and use the Batch buttons
But first you might want to create an inventory item by completing all fields and exporting it so you have a data template.