Can I create a reusable template for pages?
Live Composer plugin comes with templates for blog posts and custom post types. Pages can't have a common template as page layout should adopt to the content to make it attractive for the visitors.
How to reuse already created page design?
When you have a few similar pages it make sense to save the first designed page in the Design panel. You will save some time creating other pages based on this first page layout.
Please, keep in mind that saved page designs are not linked like the posts templates. Changing one of those pages won’t automatically change all of them.