Q. How can I export favorites from Edge?
A. Edge stores its favorites in an Extensible Storage Engine (ESE) which is located in folder %localappdata%\Packages\Microsoft.MicrosoftEdge_8wekyb3d8bbwe\AC\MicrosoftEdge\User\Default\DataStore\Data\nouser1\120712-0049\DBStore\spartan.edb. There is also no native export in Edge.
Fortunately a tool exists at http://www.emmet-gray.com/Articles/EdgeManage.html that exports the content of the database to a HTML file which can then be imported into any browser. It also enables you to arrange favorites and other types of favorite actions. You must close Edge to use the tool.