How to view table contents in Mysql Workbench GUI?

Select Database , select table and click icon as shown in picture.

Open a connection to your server first (SQL IDE) from the home screen. Then use the context menu in the schema tree to run a query that simply selects rows from the selected table. The LIMIT attached to that is to avoid reading too many rows by accident. This limit can be switched off (or adjusted) in the preferences dialog.

This quick way to select rows is however not very flexible. Normally you would run a query (File / New Query Tab) in the editor with additional conditions, like a sort order:

To get the convenient list of tables on the left panel below each database you have to click the tiny icon on the top right of the left panel. At least in MySQL Workbench 6.3 CE on Win7 this worked to get the full list of tables.

See my screenshot to explain.

Sadly this icon not even has a mouseover title attribute, so it was a lucky guess that I found it.

Inside the workbench right click the table in question and click "Select Rows - Limit 1000." It's the first option in the pop-up menu.