Bookmarks->Organize Bookmarks, double-click on Bookmarks Menu. Using the Scroll bar scroll through the bookmarks and highlight the ones you want to move, holding down the Ctrl key to highlight more than one at a time. Once you have selected all the bookmarks you are interested in, right-click within the highlighted bookmarks, click New Folder..., name the folder, the click Add. This will drop all the highlighted Bookmarks into the new folder.