To do Alt + H B A on Mac in Excel, download and install Accelerator Keys, then press Option, followed by H, B, A.
Command: All Borders
This is how to do Alt + H B A 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 B a applies borders to all sides of every cell in the selected range, including interior borders between cells. This creates a grid effect where each individual cell has its own complete border. It’s commonly used for creating tables, data grids, Structured layouts where you want clear visual separation between all cells.