Upload 'tsv' file to Google Colab / Jupyter Notebook
You first need to upload your file. The io.BytesIO only reads from the uploaded. So first run:

from google.colab import files
uploaded = files.upload()


and select the file you would like to upload.

Also, when you load it into your pandas, you need the sep='\t':

tsk = pd.read_csv(io.BytesIO(uploaded['train.tsv']), sep='\t')