You can create new widget areas to use on particular pages and manage them like other widget areas on your website.
Effata Widget Areas is the new WordPress plugin that lets you do that without editing your theme. The widget areas can be added to any page, category, or tag.
Simply start by installing-activating Effata Widget Areas plugin on your WordPress site.
Once activated, you would be able to create widget areas from the Appearance -> Widget Areas page, as shown in the given screenshot.
You can register new widget areas, set where you want them to display, the position and visibility range, etc. Once the widget area is registered, you can display it via shortcode on any page or via PHP code in your theme, and then start managing it like other widget areas using the widgets page in the appearance menu.