Tablets are the most shelf-stable choice and retain their potency over a longer time (2-3 years) compared to liquids, powders and most capsules. Tablets can be offered in a wide range of sizes and shapes. Tablets are coated with sugar or similar substances, which means that the drug contained in it will not immediately enter the blood stream. But, the drug in the capsules is known to enter the blood stream immediately. As long as you choose product from a reputable manufacturer, formulate it based on nutrient synergy and take it as directed, you do not need to worry about absorption issues with tablets.
Drawbacks: Large tablets can be hard for some people to swallow (they can be crushed just before use). Tablets do not offer the flexibility of dosing that liquids and powders do.