Hi, you have to enable the context menu for FCKEditor, which you can do by editing file 'public/assets/javascript/fckeditor/fckconfig.js' and change line 170 from:
FCKConfig.ContextMenu = [];//'Generic','Link','Anchor','Image','Flash','Select','Textarea','Checkbox','Radio','TextField','HiddenField','ImageButton','Button','BulletedList','NumberedList','Table','Form','DivContainer'] ;
to:
FCKConfig.ContextMenu = ['Generic','Link','Anchor','Image','Flash','Select','Textarea','Checkbox','Radio','TextField','HiddenField','ImageButton','Button','BulletedList','NumberedList','Table','Form','DivContainer'] ;
Now refresh your browser and you will be able to insert rows and cells by right clicking the table.