Web browser or extension to move multiple tabs between windows in a single action
You might run a script like this in AppleScript Editor:

tell application "Safari"
    set w to window 1
    set namelist to name of tabs of window 1
    repeat with i from 1 to (count namelist)
        set item i of namelist to (i &amp; " " &amp; (item i of namelist)) as text
    end repeat
    set answer to choose from list namelist with multiple selections allowed
    if answer is false then return
    make new document
    repeat with i in (reverse of answer)
        move tab ((word 1 of i) as integer) of w to beginning of tabs of window 1
    end repeat
    delete tab -1 of window 1
end tell


This moves the current tab and all tabs right of it to a new window:

tell application "Safari"
    set l to tabs of window 1 where index ≥ (get index of current tab of window 1)
    make new document
    repeat with t in (reverse of l)
        move t to beginning of tabs of window 1
    end repeat
    delete tab -1 of window 1
end tell


Both scripts reload each tab though.

I normally just copy the URLs of tabs as text:

set text item delimiters to linefeed
tell application "Safari" to URL of tabs of window 1
set the clipboard to result as text


I can then for example copy part of the lines and run open $(pbpaste).