Years ago, dive tables were how everyone dived. Now, the majority of divers dive with a wrist-mount computer and it makes sense.
The computer calculates depth, time, speed of ascent, and NDL in real time. Tables give you a static plan. If you change depth during a dive, it updates. Tables are set before you get in.
Watch-style computers are the most common buy these days. These are compact, readable underwater, and you can use them as a daily watch too. Hose-mounted computers are an option but not as many buyers choose them these days.
Entry-level computers run about $250-400 and cover everything the average diver needs. Features include depth tracking, bottom time, NDL, log function, and usually an entry-level freediving mode. Stepping up to webpage mid-range includes wireless air monitoring, improved screens, and additional mix options.
What people forget is how the computer handles. Some models are more conservative than others. A cautious setting results in shorter NDL. Liberal ones give more time but at a thinner safety margin. Neither is wrong. It comes down to personal preference and your diving background.
Worth talking to the staff at a dive shop who uses various models before you decide. Good dive stores will offer a straight answer on what's good versus what's hype. Most good dive stores put out product guides and comparisons online too