Not only can you read comments left in an Excel 2016 workbook, you also can edit those comments. When you have an Excel 2016 workbook with sheets that contain a bunch of comments, you probably won't want to take the time to position the mouse pointer over each of its cells in order to read each one.
For those times, you need to click the Show All Comments command button on the Ribbon's Review tab (or press Alt+RA). When you click Show All Comments on the Review tab, Excel displays all the comments in the workbook (as shown here).
With the Review tab selected in the Ribbon, you can then move back and forth from comment to comment by clicking its Next and Previous command buttons in the Comments group (or by pressing Alt+RN and Alt+RV, respectively). When you reach the last comment in the workbook, you receive an alert box asking you whether you want to continue reviewing the comments from the beginning (which you can do by simply clicking OK).
After you finish reviewing the comments in your workbook, you can hide their display by clicking the Show All Comments command button on the Review tab of the Ribbon or pressing Alt+RA a second time.
To edit the contents of a comment (whether or not it's one you created), select it by clicking the Next or Previous command button in the Comments group of the Review tab and then click the Edit Comment button (which replaces New Comment) or right-click the cell with the comment and select Edit Comment from the cell's shortcut menu. You can also do this by selecting the cell with the comment and then pressing Shift+F2.
To change the placement of a comment in relation to its cell, you select the comment by clicking somewhere on it and then position the mouse pointer on one of the edges of its text box. When a four-headed arrow appears at the tip of the mouse or touch pointer, you can drag the text box to a new place in the worksheet. When you release the mouse button, finger, or stylus, Excel redraws the arrow connecting the comment's text box to the note indicator in the upper-right corner of the cell.
To change the size of a comment's text box, you select the comment, position the mouse or touch pointer on one of its sizing handles, and then drag in the appropriate direction (away from the center of the box to increase its size or toward the center to decrease its size). When you release the mouse button finger, or stylus, Excel redraws the comment's text box with the new shape and size. When you change the size and shape of a comment's text box, Excel automatically wraps the text to fit in the new shape and size.
To change the font of the comment text, select the text of the comment (by selecting the comment for editing and then dragging through the text), right-click the text box, and then click Format Comment on its shortcut menu (or you can press Ctrl+1). On the Font tab of the Format Cells dialog box that appears, you can then use the options to change the font, font style, font size, or color of the text displayed in the selected comment.
To delete a comment, select the cell with the comment in the worksheet or click the Next or Previous command buttons on the Review tab of the Ribbon until the comment is selected and then click the Delete command button in the Comments group (Alt+RD). Excel removes the comment along with the note indicator from the selected cell.
You can also delete all comments in the selected range by clicking Clear Comments from the Clear button's drop-down menu (the one with the eraser icon in the Editing group) on the Home tab of the Ribbon (Alt+HEM).