This is a first, I've never come across this one before and I've tried deleting the contact from both contacts and FaceTime and it still appears.
I'm not sure if this icon actually signifies that you have FaceTimed them as I have a couple with the icon and I haven't FaceTimed them at all. So these contacts may have the icon where they have FaceTime activated.
I will move this to our Help Forum where hopefully others will have an answer for you.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.