Tallinn offers a variety of accommodations ranging from hostels to 5-star hotels.
The Academic Hostel (NB: two bedrooms share a bathroom & kitchen) is the accomodation place nearest to the colloquium venue: https://www.academichostel.com/en/rooms-and-prices/
In the city center are many hotels and also some hostels. The campus and colloquium venue is about 30 min by trolly/bus from the Old Town (city center), e.g. by trolly 1,3,5 (see "Location -> Transportation")
St. Barbara Hotel (http://www.stbarbara.ee/en/) is just outside the Old Town and close to a direct trolly bus connection with the campus (trolly bus 3).
The Park Inn (Meriton) (https://www.parkinn.com/hotel-meriton-tallinn) is close to a direct trolly bus connection with the campus (trolly bus 5).
The Nordic Hotel Forum () is located close to the Viru shopping center and also close to the Old Town.
There are many more hotels in and around the Old Town.