You may want to work on the Grub Menu while booting in the Ubuntu but the problem with this thing is that it appears only for 3 second by default which is very less for sure.
The Grub Menu can be seen by pressing the Esc key while booting up in Ubuntu. It can also appear if you have made it to show by default as we described earlier. Using the following procedure you can easily change the Grub Menu timeout.
You need to open the menu.lst file in a text editor, just type the following command in the command prompt
sudo gedit /boot/grub/menu.lst
Watch out for the following section in the file that opens
## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
So to change the time, just change the value after “timout” to a number (in seconds) that you want to display the Grub Menu. Save the file and reboot.