There are two ways you can export an Item report to a spreadsheet.
1.With the Item open, select the Item report in the ribbon, then select Print. In the Print dialog box, change to Export and select the Xlsx Report File in the Type field. This can then be saved locally.
2.With the Item open, select the Item report in the ribbon, then select the Excel icon beside it. This will show each report pipeline in a separate sheet, ie. Item, Item Names, Item Stock.
Further information