To do Alt + h w on Mac in Excel, download and install Accelerator Keys, then press Option, followed by h, w.
Command: Wrap
This is how to do Alt + h w on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + h w toggles text wrapping in the selected cells. When enabled, long text will wrap to multiple lines within the cell instead of extending beyond the cell border.