I was offered once to participate in 'finishing' the Eucharist after It had been taken back to the altar. I was 6 - 8.
I have only seen the Priest do this. Who is allowed to handle the chalice?
It might have been "uncanonical" a bit.
Or, your participation may have been to read the prayers of Thanksgiving; I've seen that happen before, where young men of the parish are invited to read the prayers of Thanksgiving for the priest/deacon as he consumes, both as a service to the clergyman, and also to expose the fellow to the beauty of the prayers.