If the file is large, you may not want to load it entirely into memory at once. This approach avoids that. (Of course, making a dict out of it could still take up some RAM, but it's guaranteed to be smaller than the original file.)
my_dict = {}
for i, line in enumerate(file):
if (i - 8) % 7:
continue
k, v = line.split("\t")[:3:2]
my_dict[k] = v
Edit: Not sure where I got extend from before. I meant update