Is there a way to restrict access of editing certain fields on an entity form to specific roles?

Yes. You can use a Workflow for that, and apply the Workflow to a specific custom form and role. Using Set Field Display type in the Workflow Action. Other option is to set the restrictions in the field definition itself (in the Access tab), but it's a solution that I don't prefer over the workflow.

Thank you, I see the workflow use for it

Workflow is your best option, doing the restriction in the field definition tends to be a bit wonky!

another option is to create a custom form --> disable all the fields except the desired ones --> assign the form as preferred form for the role, no workflow needed

Thanks for the suggestion, however this is for a customer record so that would not work well. I created a workflow, you can actually use one published in SuiteAnswers for Invoices and apply it to entity records as well. https://suiteanswers.custhelp.com/app/answers/detail/a_id/74519/loc/en_US