Copy Selected Tabs to Clipboard от Piro (piro_or)

This addon adds "Copy Tabs to Clipboard" item to the tab context menu. You can copy tabs in your favorite format, like Markdown, HTML, or others.

It is recommended to set "dom.events.asyncClipboard.dataTransfer" to "true" via "about:config", if you use any rich text format.

You'll see more examples at https://github.com/piroor/copy-selected-tabs-to-clipboard/blob/trunk/README.md#example-copy-formats

You can assign arbitrary keyboard shortcuts for each action via "Manage Extension Shortcuts" in the addons manager.
There is no default shortcut, thus you need to set it manually.