Additional Resources
Now that you have a better understanding of how screen readers interact with simple tables, you should take a moment to review resources that can assist you with making more complex tables accessible. The W3C Web Accessibility Tutorials website has a number of resources to aid with making your complex tables accessible.
I have highlighted a few below:
Adding a Table Caption & Summary
In addition to providing detailed descriptions for table captions and summaries, this resource offers different approaches for how to add a table summary
Making tables with irregular and multilevel headers accessible
This resources provides multiple examples of tables with multilevel and irregular headers, as well as strategies for making them accessible.