Sundry can be an adjective or a noun meaning,"several, various, diverse." Sundries is the plural version of sundry's noun form, usually applied to necessary items e.g. groceries that are not significant enough to mention/list individually.

You could say "I have sundry fish in my aquarium", which means you have a large variety of different fish.
Or you could say, "I packed my sundries for the trip," which basically means you packed various necessities such as toiletries, underoos, clothes and the like.