Generic chargers work with Samsung Tablets, but this usually causes devices to charge at slower rates. Brand name devices usually work optimally only with original chargers and accessories.
Original Samsung chargers normally charge the device at a speed of 800 to 1000mA, compared to approximately 350mA with a non-Samsung alternative. This means that devices that normally take two or three hours to charge with original chargers take considerably longer with generic counterparts.
Some people use a technique to trick brand name devices into charging faster with generic chargers, but it is risky and may result in damaging chargers and tablets.