Help:Wikitable
Introduction to tables
How and why
Editing tables
The basics
Expanding tables
Adding rows and columns
Summary
Review of what you've learned
Tables are a common way of displaying data. This tutorial provides a guide to making new tables and editing existing ones. For guidelines on when and how to use tables, see the Manual of Style.
The easiest way to insert a new table is to use the editing toolbar that appears when you edit a page (see image above). Clicking the button will open a dialog where you define what you want in your new table. Once you've chosen the number of rows and columns, the wiki markup text for the table is inserted into the article. Then you can replace the "Example" text with the data you want to be displayed.
Tables in Wikipedia, particularly large ones, can look intimidating to edit, but the way they work is simple.