Refactor jQuery multiple click() event handlers

You can simply put your common code in a function

function giveItAName(htmlValue,self){

 $("#page").empty().html(htmlValue);
 $("a").removeClass("active");
 $(self).addClass("active");
}

And call this function accordingly

('#tab1').click(function() {
giveItAName("<p>Here is our menu: Crispy Duck, Shrimp Tempura, Christmas Roll</p> ",this);
});

And so on ...

You can combine these using a helper function with a closure.

function bindTabClickToSetPageContent(selector, content) {
    $(selector).click(function () {
        $("#page").html(content);
        $("a").removeClass("active");
        $(this).addClass("active");
    });
}

bindTabClickToSetPageContent("#tab1", 
    "<p>Here is our menu: Crispy Duck, Shrimp Tempura, Christmas Roll</p>");
bindTabClickToSetPageContent("#tab2", 
    "<p>We're located at: 13352 Minnieville Rd., Woodbridge, VA</p>");
bindTabClickToSetPageContent("#tab3", 
    "<p>We can be reached at: (555)555-5555.</p>");

Note: I dropped the call to empty since html performs the same function before replacing the content.

You can do this in one function that takes into account the ID of the element clicked on to determine what HTML to add to the DOM:

//the idea here is to match the number of the tab (#tab1 being number 1) with the data to display for that tab, the blank first index is because there is no #tab0
var tabData = ['', '<p>Here is our menu: Crispy Duck, Shrimp Tempura, Christmas Roll</p>', '<p>We\'re located at: 13352 Minnieville Rd., Woodbridge, VA </p>', '<p>We can be reached at: (555)555-5555.</p>'];

$('#tab1, #tab2, #tab3').click(function() {

    //get the index of the clicked tab via its ID
    var index = parseInt(this.id.replace('tab', ''), 10);

    //update DOM based on the index of the tab
    $("#page").empty().html(tabData[index]);

    //update links, I recommend adding a class to these links so you don't mess with others in the DOM
    $("a").removeClass("active");
    $(this).addClass("active");

});

Here is an updated JSFiddle: http://jsfiddle.net/Q4zVH/3/

You could also select your tabs by some other type of identifier, like a class, which would make this easier to expand.