Thanks for identifying the bug and pointing out this UX contrast issue. I’ve made some updates to the component:
Fixes above mentioned bug:
https://github.com/discourse/discourse-table-builder/commit/7e65777187ace26214915ff0bacb8abd0623d409
UX: Improves context menu text color:
https://github.com/discourse/discourse-table-builder/commit/213c42eb6b4d0551e68683beaf41c09129dac651