Select the cell where you want the bullet
Press Alt+7 on the numeric keypad
Press Alt+0149 on the numeric keypad
Copy and paste a bullet character like • into the cell
Use Insert > Symbol and choose a bullet character
Type =CHAR(149) in a formula if your system supports it
In Windows, hold Alt and type 7 or 0149 using the numeric keypad
On Mac, press Option+8
To add multiple bullets in one cell, press Alt+Enter for a new line and repeat the bullet
To create a bulleted list in a cell, combine bullet characters with line breaks