You should press CTRL+A to select the entire document text.
Control + a
Ctrl + A
The keyboard shortcut is: Ctrl Shift *(asterisk)
Select the entire table. Then use the paragraph formatting options to centre it. Alternatively, press the Ctrl - E shortcut combination.
Command A = Select All
Right click on the shortcut, change it's name. Right click on the shortcut, select properties, and change what the icon looks like.
That may vary from one program to another. It may also vary according to the language. Often it is Ctrl-A, but for a specific program (and language), just look for the "Select All" command in the menu - the shortcut key is usually displayed next to the command.
On top of screen go to Edit then Select All
Shortcut keys
Ctrl+A
The Shortcut key can be used for selecting some commands. There are also many specific shortcut key combinations for commands and there are the Function keys.
From the Finder's File menu select New Folder (or use the keyboard shortcut - Shift, Command, N) or right click on the Desktop and select New folder from the menu.
Press the Ctrl+A buttons using keyboard. or Click on the Selet all icon which will be in top left side of the sheet it will select the entire worksheet