P245/55R19 is the tire size. That's a pretty tall tire. 2-1/2" taller than your 205/75R15 stock tires. If your truck is a 2.2, acceleration will suck. Your speedo will be off 5mph at 60 and more than likely your ABS will quit working because of the mismatched tire sizes.
They might rub a bit. Depending on the wheels. 5x120 is NOT the S10's bolt pattern. It is 5x4.75". (120.65). I'm going to try not to start the age old unresolved debate of whether or not you can "make" them fit. If you want to research the subject do a search here or on Google. There a literally 1000's of posts on the subject.
Much more important to answering your question is what is the offset of those wheels. If it's near 0 you should be fine. A lot of newer wheels are in the +50MM range. On a 2wd truck that can be problematic. You'll need 2.5" spacers to run them. That's another endless debate. Safe or not? Hubcentric or not? Finding hubcentric for a 2wd pickup can be difficult.
Bottom line - there are better choices available to you.
