No, there are no problems. After all, a server is basically just a computer like yours, with a file system like yours. Putting your website files on the server is like copying your files from one directory into another on your computer, only you copy them from your computer on the other, remote computer.
If you have connected to your server with an FTP program, usually you will see your local files on one side and the remote files on the other side. The remote site is just a directory, too, and whatever you put in there (it doesn’t have to be HTML files, you can put any kind of file since – remember – it’s just a computer with a harddrive, too) you can access via your browser. If you put a file called “test.txt” and put in your browser’s address bar “
http://example.com/test.txt” (example.com being your domain) the browser shows you the content of that text file. Likewise, if you put a directory there with the name “hello” and in that directory you put an image called “test.jpg” you can access that file in your browser by writing “
http://example.com/hello/test.jpg”.
You don’t
have to have an index.html file in order do be able to access the files on your server but such a file is usually the default that is called up when you don’t specify a file name in the URL (e. g. if you just input
http://example.com it will actually call up the
index.html, so basically it will do the same as if you had written
http://example.com/index.html).
Since that server space is just a regular directory, too, it behaves as such and you can have many files in there, as in the directories on your own computer, e. g.:
Code:
/css
/img
about.html
contact.html
favicon.ico
index.html
robots.txt
The first two are directories where you can put additional files, the other ones are HTML/text/image files. And you can access all these files directly by typing the respective file path into the browser’s address bar.
Before you post, read our: 
Upload html files on Server[request immediate help]
