That sounds bizarre and certainly has nothing to do with Catholicism. Where in Europe have you seen this? Putting flowers in front of statues is a show of respect but no purpose is served by food or drink. It would have to be some kind of pagan syncretism.
Idolatry is displacement of God in one's heart with something else. God Himself raised up the Prophets, Apostles, and Saints to inspire His people. The normal, healthy veneration of saints has been universal within the Church since the time of the earliest Christians. It helps keep us mindful of God's power by serving as a well-proven channel of His miracles.
"The Roman Catholic Church, in its pagan form, unofficially came into being in 312 A.D., at the time of the so-called "miraculous conversion" to Christianity of the Roman Emperor Constantine. Although Christianity was not made the official religion of the Roman Empire until the edicts of Theodosius I in 380 and 381 A.D., Constantine, from 312 A.D. until his death in 337, was engaged in the process of simultaneously building pagan temples and Christian churches, and was slowly turning over the reigns of his pagan priesthood to the Bishop of Rome. However, the family of Constantine did not give up the last vestige of his priesthood until after the disintegration of the Roman Empire -- that being the title the emperors bore as heads of the pagan priesthood -- Pontifex Maximus -- a title which the popes would inherit. (The popes also inherited Constantine's titles as the self-appointed civil head of the church -- Vicar of Christ and Bishop of Bishops.)
Prior to the time of Constantine's "conversion," Christians were persecuted not so much for their profession of faith in Christ, but because they would not include pagan deities in their faith as well.