If things are being hashed evenly, and you have a 100 bucket table, putting 200, 300, etc. elements into the table isn't a terribly big deal, because it's just not slow to traverse a few nodes of a linked list. Of course, there's no reason not to make the table much bigger--it's just an array of pointers, make it 1,000,000 entries and you're still within a few megabytes.

Now, if someone wants to be a jerk, and figures out how to easy collide on your hash function, then you could have problems. He could stuff 1 million elements into the same hash table element, which will suck for linked-list traversal. So get a good hash algorithm :)