Dashboard Editing

Is there a way that a page can be setup so that in the dashboard I could edit multiple blocks of content on that same page? Say, for instance, that I have 3 columns on the page in which I would like to have content. Is there a way to make more than one region editable without making each area a separate post? I could make a page that pulls all the posts with a certain tag or category and use those posts to populate the regions of the page, but then I would have no way of previewing the page after updating only 1 of those posts unless I actually publish the post. I want to make it so that I can edit all the regions at the same time and preview the changes to the page before actually publishing. Is this possible? I also copy links of the site here for more information.