What is brought to the altar along with the unconsecrated bread and wine at the beginning of the liturgy of the eucharist?

Normally, the procession up to the altar at the beginning of the Liturgy of the Eucharist is to bring the gifts to be used for the sacrifice, in other Words, the bread and the wine, as you mention in your question. However, if there is a collection at that Mass, then the collection would also be brought to the altar as it represents the gifts of the people as well.