It used to be possible to do this, and it is even documented here: https://lingualibre.org/wiki/Help:Create_your_own_lists
Now there seem that there's no direct option to do that, isn't it?
Actually, this feature dissapeared in the new version of the Lingua Libre website. So the documentation should be updated. Meanwhile, this task remains open to ask for this feature comes back.
You can still copy a list of words in plain text; the Record Wizard is able to parse them if words are separated by the # character. Concerning Lingua Libre Bot, it seems it does not add anymore pronunciations on Lexeme since some time. Currently there is noone to debug or restart the bot so Lingua Libre Bot will probably not work in the coming weeks (months?).
That's say, in normal time, the answer to your question is yes.