A throttled API is a common problem, especially if you’re just starting. Loosely speaking, the more sales you drive, the more API requests you can make.
Here's the help doc page which outlines how they calculate this: https://webservices.amazon.com/paapi5/documentation/troubleshooting/api-rates.html
If you're seeing an error message on the settings page, but you're still able to perform searches that's fine but you may still run into throttling issues. When we check on the settings page (any time the page loads) we fire off a bunch of requests in a row via the PA API for each locale that you have set up with Table labs so that's why you may see error messages on the settings page but still be able to perform searches.
The solution to avoid throttling issues is to start driving more sales as an Amazon affiliate so that Amazon will grant you more requests via their API. Worst case you may need to create some links manually until you're driving enough sales to get rate increases and can continue using Table Labs again.