How to centralise a newly created table without using source code

I rarely bother the forum ..... but one item infuriates me and I cannot find the answer on the forum or on Google.

Simply ..... how do I quickly centralise a table that I create [not using the source code]?  I am HTML literate but I seem to eventually centralise by guesswork ... this time 'no'.  I want the table at top of main index page as a member has died and I want a tasteful black announcement box  

Many thanks.

create a 100% table with 3 cells across make them 20% 60% 20%

use the center text button to center the text in the center box.

Another option is to right click on the table (using windows). and choose "Table Properties"
From the dialog box that opens, go to the "Alignment" dropdown box and choose "Center"