Using Lumen within Wordpress for simple things?

Hi, I'm a little new to Laravel, I studied it last year, and just did some test things. Now I have to manage some custom db tables within a wordpress installation. Something REALLY minimal: just save form data to tables and give an admin wordpress user the ability to download an xls (or spreasheet like) of the db (just by clicking a button on the wp backoffice). For now I don't need an API. Basically, I was thinking of Lumen because I would like just an ORM, thus maybe Eloquent.

I the future it could become more of a real app with user auth, api, etc... For now, just what described above.

My concerns are:

• can I use Lumen just to use Eloquent?

• can I call Eloquent methods from a plain php file (the file where I collect user data from a form and send emails)? in other words, can I use Lumen/Eloquent from 'outside' their environment? Just like (I think) If I used only Symphony's Doctrine ORM?

I'd like to use Lumen also because I'd like to try it and because as I said, I could be asked in the future to add some more feature to the whole thing, and thus rapidly having the need of user auth, some web pages, etc..

How would you suggest to proceed?