How to make a sortable table in frontend?
I can think of a couple ways to pull this off but Craft has many of the pieces already in place.


I'd create a new Channel, name it Organizations. You can add whatever fields you want in there (like address, city, etc.)
To leverage Craft's relations,  create a new field (Organization) that relates back to the Organization channel you just created and add it to the user's profile.


That's the information architecture bit. It'd be up to you how you want to collect the information. Maybe when a user registers for their account for the first time, you'd ask for details. 

Then in a custom plugin, you'd probably want to validate to make sure the organization entry didn't already exist before creating a new entry in Organizations channel. Then set the relationship of that newly created entry to the User.

The great thing about Craft is the UI is up to you. So you might use any number of table sorting plugins. 

Craft can even handle the Pagination for you. I think DataTables does ajax pagination out of the box, so your Twig template could just need to feed it the data.