Sometimes, you may be surprised to discover that a Claris CAD document with few or no objects occupies a large amount of space on disk. This is because Claris CAD "remembers" recently deleted objects for the purposes of the Undo command. If you delete several objects from your drawing, save the file, then open the file, you will be able to choose the "Undo" command; all your objects will re-appear.
To permanently delete your objects, you may want to copy the objects into a new document and save the new document. Or, perform some other operation that will force the "undo" command to store something less dramatic. Simply drawing a line will put the line into the undo buffer and delete the previously stored information.