It's ok to buy any tool you want and, one way or another, a table saw will probably be on the list of must have's.
I have to say though that that kind of question scares me a bit every time it pops up, frequently, because of the questions left unasked.
Take a table saw for example. There can be so many factors that contribute to the selection of this relatively expensive investment. Things like budget and space.
What kind of table saw, bench top, contractors, cabinet, hybrid? Which will fit your needs, not use up so much of the budget you can't get the other things you will need, not take up so much room in whatever you have for shop space that you can't add other tools and/or leave you with no room to actually work in?
Woodworking isn't really, as much as some may like to think otherwise, a matter of tools, but rather a development of knowledge and skills.
It's nice to run out to the local tool/toy store and fondle all the goodies. You aren't alone there. We all do it, we all check out the catalogs when they come in and start to do a Pavlov when we see what the new latest greatest tool is.
Unfortunately, unless you have a budget that Bill Gates would envy, impulse buying is not something you really want to get into when it comes to your tools. Even "simple furniture" requires more in the way of tools the a saw. At it's simplest it will require equipment for measuring, clamping, sanding, shaping, finishing, etc..
That is not even touching on things that you should have at least a nodding acquaintance with. Things like appropriate joints, how to make them, what you need to make them, wood movment, how proper selection of joints figures in with wood movment, appropriate finishing, how to apply it, best way to apply it, and for all of the above, what options are available that will accomplish the tasks. Then there is the care and maintained of the tools you have.
I'm not trying to scare you off, it isn't rocket science. Window shop to your hearts content but before you start laying out big bucks do some study on the subject, take a course if the local adult ed place has one, find a mentor, read, build a library.
Tools can't think for you. You have to be able to make them do what you want. IE a table saw can't do anything a hand saw does it just makes it easier. It is still you that has to decide where to cut, what to cut, and why you have to make the cut.
Pick a simple project. Plan it on paper and try to figure out all the options you have in tools to accomplish the tasks required. There will be several. Finally, Try too arrive a realistic assessment of what to get in light of your budget and work space. Then spend the money, make some sawdust, and start to build you skills base.
Good luck.