This plugin lets you redirect clipboard text into a separate note, which is then embedded at the cursor position in the active note.
Here it is being used in combination with the Plotly plugin, and the clean-embeds CSS snippet:
Redirection rules are currently specified as regex, but I plan to allow pasting by a rule to be activated by a keyboard shortcut.
You might also be interested in these other plugins (not by me): Note Refactor and QuickAdd.