Help:Introduction to tables with VisualEditor/4
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Introduction to tables
How and why
Editing tables
Updating information
Adding new tables
Much easier than it used to be
Expanding tables
Adding rows and columns
Summary
Review of what you've learned
To add a column or row, you need to define where you want to insert it. Once you've selected a cell, a triangle will appear at the top of the column, and the left of the row.
Clicking on the top triangle allows you to add a new column before or after the selected one (or delete it). Similarly, clicking the left triangle allows you to add or remove rows.