Microsoft has recently released a new update for Office Insiders on Slow Ring. The latest update bumps the office to Build 17.8067 and brings Collaborative Editing which allows you and your colleagues to open an Excel Workbook and collaborate together. This will allow your co-authors to see changes in almost real time. Below are the complete details of the new update.
Collaborative Editing: Work with others at the same time in your workbook. Insert recent links: Easily attach hyperlinks to recent cloud-based files or websites, and create meaningful display names for people using screen readers. Open more files: You asked for it! You can now open files that contain ink.