What does por favor aspirar oficina mean?

Literally translated, it means: "Please, to vacuum office." -- and has no true meaning in Spanish (though if said to a Spanish-speaking person, they would understand you, and probably have a good laugh at your expense)

To say it properly, you would either say:

(Haz) Favor de aspirar la oficina or

Por favor aspire la oficina.

Note the ending change on the second sentence choice. The verb is being used as a command and therefore, giving the context of the sentence, one would assume that it should be spoken in the Usted.