have both excel and the PowerPoint presentation open.
Select the first cell in excel you want to use and select to copy the cell
Switch to PowerPoint, locate the slide and tap inside the placeholde where you want to use the excel cell content and then select the paste dropdown and then paste special, follow the dialog box and select paste link (select Microsoft Exle Worksheet Object) and tap ok.
Save and close the PowerPoint
Switch back to excel and change the cell vale
Switch back to PowerPoint and open the presentation and you will be prompted to update the links tap update links and you should see the changes.
It's a solution but you would need to set it up manually