Years ago, dive tables were how everyone dived. At this point, most recreational divers use a wrist-mount computer and for good reason.
The computer monitors depth, bottom time, speed of ascent, and no-deco limits in real-time. Dive tables are a fixed calculation. When you change depth during a dive, the computer recalculates. Tables don't.
Wrist-mount computers are what the majority of divers go for at this point. They're compact, readable underwater, and you'll use them as a regular watch too. Console-mount computers are available but fewer buyers go that way anymore.
Entry-level computers start around $300-odd and cover everything most divers would need. Features include depth tracking, dive time, NDL, dive logging, and often a basic apnea mode. The $500-800 range gets you transmitter compatibility, better displays, and additional mix compatibility.
The one thing people don't think about is conservatism settings. Certain algorithms are tighter than others. A conservative algorithm means shorter bottom time. Liberal settings extend bottom time but at a thinner safety margin. It's not right or wrong. It's your style and experience level.
Ask the staff at a dive shop who's used various brands before you decide. They'll offer honest opinions on cairns dive computers which ones hold up and what isn't just marketing. Most good dive stores publish product guides and rundowns online as well