Hi AB,
Due to browser limitation of pasting from system clipboard using API and context menu options is restricted. So, only paste options is disabled in context menu.
Alternatively, you can use the keyboard shortcuts,
Cut: Ctrl + X
Copy: Ctrl + C
Paste: Ctrl + V
If you want to copy/paste content within editor, you can set enableLocalPaste as true,By enabling this property, allows you to cut/copy and paste content within control using context menu.
To perform paste content from outside of editor, you have to set enableLocalPaste as false and need to implement a server side interaction.
Please check below documentation for reference.
https://ej2.syncfusion.com/documentation/document-editor/clipboard/#local-paste
https://ej2.syncfusion.com/documentation/document-editor/clipboard/#enablelocalpaste-behaviour
Please let us know if you need any further assistance.
Regards,
Suriya M.