Hide all but $(this) via :not in jQuery selector

$(this).siblings().hide();

Traversing/Siblings

$("table.tr").not(this).hide();

As an aside, I think you mean $("table tr") (with a space instead of a dot).
The way you have it, it selects every table which has a class of tr (eg, <table class="tr">), which is probably not what you want.

For more information, see the documentation.

If you want to combine not() with some other selectors, you can use add():

$('a').click(function(e){
  $('a').not(this).add('#someID, .someClass, #someOtherID').animate({'opacity':0}, 800);
});

This would fadeout all other links, but the clicked one, and additionally fadeout some chosen ids and classes.