View multiple files as tabs
The tab bar displays currently open files as tabs below the ribbon area. You can open several files in the same window and use the left/right arrows at the far right of the tab bar to navigate, or reorder files by simply dragging and dropping a tab within the same group. If you want to open one of the files in new window, drag the tab away from the bar and release.

A. Grouped open files B. Left and right arrows for navigating all open files C. A list of open files
The right-click menu of a Right PDF Reader file tab provides the following actions:
-
Open File in New Tab. Select a file and open it in a new tab.
-
Save Current/Save All. Save the file you are currently viewing or save all open files in this window.
-
Close Current Tab/Close All. Close the file you are currently viewing or all open files in this window.
-
Print Current Tab/Print All Tabs. Print the file you are currently viewing or all open files in this window.
-
Open in New Instance. Open the current file in an new window. The file will be removed from the tab bar of the previous window.
The tab bar feature is on by default. You can deselect the Open documents as new tabs in the same window option at General > Startup panel of the Preferences dialog box to always open a document in a new window.

The Open documents as new tabs in the same window option is checked by default. Deselect it to open files in new windows.
Note: Right PDF does not support reattaching the tab back to the tabbing bar.