In general you'd want water based finishes in satin or even matte. Oil based finishes tend to add an orange tint to the wood, even if the finish is not colored. Water based finishes are much more transparent, and will have much less impact on the natural color of the wood. Water based polyurathanes are your best bet.
Specifically for the Ikea Gerton, according to Ikea's website, it comes pre-oiled. This means that a water based finish will have trouble adhering to the wood. Ideally you should sand the table to bare wood, then finish with the water based finish. Note that sanding the wood to remove the oil will probably change the appearance of the table top (up to you to decide if this is for the better or not).