Let's start with tables.
Click a grid icon and a selection box popup showing options for grids.
Similar to a table one can add/remove rows, columns, cells etc.
Drag images/text from one cell to another.
Selecting cells adding a background color. Or as in many shortcodes a background box with a defined CSS class.
rounded corners to cells (and/or images).
All visible inside the content creation area inside the semi transparent table grid.
There should be a discussion for WP 3.7 on how to improve the content creation area of WP. I bet a lot of people have a lot to say about this area of WP. An improved Ideas forum. That look better then the ideas forum today. Where it is easier to share and read ideas/features/suggestions.