This depends. The OP says that they are HTML tables so, unless he has set them to run as a server control, he will not be able to access a visiblity property. Steve is correct, however, in that a server button, once clicked, will cause a postback (reload) of your page, provided your logic works in such a way that some happens after the page is posted back.
So somethign like this:
private void Page_Load(object sender, EventArgs e)
private void Button1_Click(object sender, EventArgs e)
//do some proecessing page will refresh after the code is executed.
Here is the thing. If, for example, the button event handler only writes data to a database your page is not going to update unless you specifiy in your code that the UI should change in X way. (A table becomes visible, new data is populated, etc)
This all really depends on what you are doing.
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