A hand caddy might refer to several different types of items that are useful around the house. Most commonly it is used to describe a device that holds and dispenses wires.
Definition of Caddy
A caddy is a container or device that is useful for storing items when they are not being used, says merriam-webster.com. Common household caddies include tea caddies and shower caddies for storing soap and other toiletries.
Wire Hand Caddies
With a typical hand caddy, you put the spools on the device's short arms and unspool wire from them. You can also dispense the spools directly from the device. This type of hand caddy is typically small, can fold and is hand-held, hence the name.
Other Uses of the Term
Because hand caddy is not a common household term and does not necessarily exclusively apply to a type of wire dispenser, some manufactures use it to describes other types of caddies, such small containers that hold soap bottles.