The self-isolation requirement doesn't apply to people arriving from a country with an infection rate below 150 per 100,000 inhabitants in the past 14 days. For the week of June 7th, these countries are:
Austria, Switzerland, Finland, Iceland, Germany, Italy, France, Ireland, Malta, Monaco, Norway, Portugal, Spain, Romania, Poland, Hungary, Croatia, Iceland, Lichtenstein, Luxembourg, San Marino, Vatikan, Slovakia, Bulgaria, the Czech Republic and the United Kingdom.
A 10-day self-isolation requirement applies on entering Estonia from a country in the European Union, the European Economic Area and the Schengen area with an infection rate above 150 persons per 100,000 inhabitants in the past 14 days.
People who have recovered from the coronavirus in the last six months or who have been fully vaccinated against the coronavirus are also exempt from self-isolation and testing.
More info: https://www.visitestonia.com/en/why-estonia/coronavirus-and-travelling-to-estonia