Hello Caio,
We had a similar experience and raised an idea quite some time ago:
Feel free to vote for the idea if it helps.
Best
Rob
The easy answer is hyring a translation bureau. So export your Excel files hand them over to the translation bureau so you can get the translated Excel sheets back. You can then import those Excel sheets again. Do make sure that for each language the give the same format back for easier import again.
Sometimes some context is needed for a correct translation but if you have a good company doing the translations they will report them back to you.
And do be aware that each language makes your model larger. Mendix did already improve this but we encountered after the fifth language in our large model that we could not deploy anaymore due to out of memory errors. Mendix improved on this but do keep this in the back of your mind if you want to add a lot of languages.
Regards,
Ronald