Final answer:
For a banquet or catered event, the napkin should be placed to the left of the salad plate as per standard table setting etiquette.
Step-by-step explanation:
When setting up a table for a banquet or a catered event where a salad is preset, the proper placement of the napkin is to the left of the salad plate. This is standard etiquette for table setting, aligning with convention and ensuring that the table looks organized and guests can easily access their napkins when seated. Generally, in table settings, the napkin's traditional spot is on the left side of the place setting or under the forks.