Is there a way in Toad Data Modeler to see all the views, tables in a left menu?
Yes, Live RE (File | Connections) would meet those requirements. As soon as you connect to the database, Live RE button will activate. Click on it and you will see a list of entites, views and synonyms . Select them (SHIFT key) and simply drag and drop them to Workspace of the model in TDM or to Model Explorer.
It is documented in the Help file, just type 'Live' in the Index tab.
This feature is also shown in this movie: