There is no need to treat reclaimed teak bowls, plates or teak root furniture items. However, if you wanted to enhance the natural colour and grain then we would recommend applying a small amount of coconut oil using a clean cloth.
The wood in the teak root tables will acclimatise to the environment that it is in. This means that when placed into a warm and dry and environment further drying will occur to the wood and may result in some grains opening up and cracks appearing. This is natural movement and rarely affects the structural integrity of the table. Using coconut oil on teak root tables aids to maintain moisture in the wood and help limit any such movement.
Reclaimed teak furniture does not require any specific treatment, however you may wish to apply a light treatment to protect against spills. Always read the manufactures label for application of a treatment and test in a small nonvisible area first. Heat protection mats should be used at all times to prevent marking.