I’m very new to software testing and am also the sole tester in my organisation so I find it really interesting what other software testing professionals do day to day - here’s my breakdown!
Role: Junior software tester (6 months)
Testing team size: 1 (me!)
On an average day I normally have a list of tasks scheduled for me to work through, I start my day by talking to the relevant developers to gather a brief and requirements on a project to start on.
I work through these tasks and send bug reports to the assigned dev ensuring I follow any test scripts and cases made earlier.
Most days I’ll have some time to spend working on test case design and test documentation for larger projects that are coming up and spend time reading for functional/technical spec’s for projects.
Towards the end of the week I normally have regression tests from bug fixes that have been pushed for testing and I also like to spend some time reading up on testing literature and anything else that’s useful to me 
I like to finish by organising work for the upcoming week making sure I have everything I need to start on Monday
This is a typical week for me although it really varies a lot depending on the type of projects and work that’s on etc - still interested to here others though!