ImportError: No module named tktable
tktable isn't part of the standard tkinter package, meaning it's not a built-in feature.
You can download the tktable package from the Sourceforge website.
tktable does not come with the Python standard distributions, unfortuntely. Thus, you need to download and copy it to your working directory or put it under the site-packages folder of your Python distribution.
tktable is a wrapper library around the homonymous library for the Tcl language and its Tk GUI toolkit. It was written by Guilherme Polo (the guy who wrote ttk). It supports images, embedded windows, varying colors and fonts, and more.
You can download a version of tktable which supports both Python 3 and Python 2 from this GitHub repository, where you can find other information on how to use it. A version for Python 2 is also available here. If you need a complete reference of all supported options, the ActiveState documentation on the Tcl/Tk TkTable might be the best way to go for now.