Dick -- Will the compressor you're looking at run air tools? Yes and no. There are some tools it will run without a problem and others it will at best struggle to keep up with. The first question you need to answer is what kind of tools will you be running with the compressor. Sanders tend to require a lot of air and they tend to need it for fairly long stretches at a time. By contrast, nailers use little air and they use it in short bursts. Screw-drills tend to fall in between. A drill might need a fair amount of air, but only for a few seconds at a time. You can answer this question with information from the maker of the tools you're considering using.
The second question you need to answer is how you'll use the tool. Generally, a sander requires a lot of air for minutes at a time. This requires a compressor with a capacity to drive the sander without relying on air from the tank (because the tank will be emptied long before you'll want to put the tool down). If, however, you tend to use a sander for only a few seconds at a time, a smaller compressor with a large tank might suffice. In such a case, the compressor, supplemented by air from the tank, will allow you to use the sander for a few seconds at a time (as long as you allow the compressor enough time to refile the tank between uses).