1998 Toyota Camry exhaust smoke

Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. Just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe, so it's not always a big alarm. The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has most likely failed. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.