@leocg In the Other Speed Dials page is a folder "Rand's iMac", which contains the Speed Dial page setup my friend created in Opera. I'm rebuilding his computer setup from scratch, starting with a fresh install of MacOS, etc. So I tried dragging this folder to Speed Dial (see the red arrow in the screenshot below). But that did nothing.

So I tried Copy and Paste: I couldn't find a way to "select" the folder, but Copy was live in the Edit menu, so I selected it, and it blinked, apparently copying something. Though now when I go to the Finder and select "Show Clipboard" under the Edit menu, something else is in the Clipboard, so apparently nothing was copied from the Opera page. So when I go to the Speed Dial page (tab) and select Paste from the Edit menu, nothing happens.
If I click on the Rand's iMac folder, it "opens" to show some 16 folders, each containing from three to three dozen links/urls. Is it necessary to copy each one (I'd guess there are over a hundred) and rebuild the Speed Dial page link by link? That's a lot of work. I was hoping there was a way to simply replace the generic, default Speed Dial (that opens when Opera is opened) with this other one that my friend built. Or at least add this set to the default Speed Dial page, then remove the preexisting links.
I've never used this feature (never used Opera), so am unfamiliar with how it works. Since I copied the Bookmarks file from the previous ~/Library/Application Support/com.operasoftware.Opera folder to the new ~/Library/Application Support/com.operasoftware.Opera folder, and all the bookmarks now appear in the Bookmarks menu as they did before. Is there a way to do the same with the Speed Dial function?