How can I view table contents in Mysql workbench GUI? I mean, not from command line.
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: