True North Outdoor Company in the UK apparently includes 2 little mesh bags with sewn webbing meant to be slipped over the grips of the paddles and provide and anchor point for the lines...
It's a pretty simple design and concept. I've always gotten away with just tying a clove hitch around the paddle, but with the elongated guide style grips I prefer, the guy-lines would often slip down. Sometimes a paddle can simply be jammed under the tarp with just plain old tension serving as a support. This little contraption looks to allow the paddles to be setup slightly ahead of the tarp which is needed in certain configurations.
Poster Neiltoo on Ni-Wild - Northern Ireland Outdoors Community - made up a similar strap device to assist setting up his hammock tarp. Here are some pics of his creation on the thread "Using Paddles with a Tarp"
Lastly, ulltralight gear site, Zpacks.com, is selling a product called "Trekking Pole Cups". These triangular Cuben fabric cups go over the handles of trekking poles but could easily be used for canoe paddles as well. Here's a closeup from their site.
Zpacks Trekking Pole Cups
Might be tinkering with something along these lines for another another winter project to work on using some scraps.