It means you are inserting huge data to your table(s)/database. Change the properties of Database and set the recovery model to simple. If it still doesn't work exec sp_spaceused and post the results to investigate further.
I don't even understand the problem. If you have log maintenance set up, or run in simple recovery, your data file will grow, and your log won't. That is normal.
What are you expecting from this post; 48MB is not a big deal and I don't think it is growing exponentially. Log files will not grow with respect to your mdf files, if it is so then there's a problem else this is expected.