Years ago, dive tables were how everyone dived. Today, the majority of recreational divers dive with a wrist-mount computer and for good reason.
The computer monitors your depth, time, ascent rate, and no-deco limits in real time. Dive tables are a fixed calculation. When you change depth partway through, it updates. Tables don't.
Wrist-mount computers are what most people buy now. These are compact, easy to read, and you can wear them as a daily watch between dives. article Console models are still around but less buyers go that way anymore.
Budget computers go for around a few hundred dollars and handle everything the average diver would need. Features include depth, time, NDL, dive logging, and sometimes an entry-level freediving mode. Mid-range gets you transmitter compatibility, better displays, and extra gas compatibility.
What buyers forget is conservatism settings. Some algorithms are tighter than others. A conservative setting results in less bottom time. More aggressive ones extend time but at reduced buffer. Neither is wrong. It comes down to your style and how experienced you are.
Worth talking to the staff at a local dive store who dives with various models before buying. Staff will offer honest opinions on what works and what isn't hype. Most good dive stores have buying guides and comparisons on their websites too