There seems to be missing documentation around what are the specific keyboard shortcuts provided by default for the quill library.
From testing I know that "Shift + Tab" can be used to navigate between elements and the toolbar but I cannot find a comprenhensive list of shortcuts available by default.
Using quill version "1.3.7" and react quill version version "2.0.0"
The only reference I can find in the official documentation (https://quilljs.com/docs/modules/keyboard/) is "By default, Quill comes with several useful key bindings, for example indenting lists with tabs. You can add your own upon initization." but it's not helpful for documenting what users can do once wihtin the rich text field.
Default shortcuts can be found in the source code here https://github.com/quilljs/quill/blob/v1.3.7/modules/keyboard.js#L141