Tables used to be the standard. Now, the majority of recreational divers use a personal dive computer and it makes sense.
A dive computer monitors your depth, time, speed of ascent, and no-deco limits in real time. Tables give you a static plan. If you go shallower partway through, it updates. Tables don't.
Wrist-mount computers are what most people use at this point. They're small enough, easy to read, and you can wear them as a regular watch too. Hose-mounted computers are available but less divers pick them anymore.
Basic computers go for around a few hundred dollars and cover everything a recreational diver requires. They give you depth, bottom time, NDL, log function, and sometimes an entry-level freediving mode. Mid-range includes wireless air monitoring, better readability, and additional mix compatibility.
The one thing new divers don't think about is how the computer handles. Some models webpage are more cautious than others. A tighter computer results in reduced NDL. Looser ones allow longer time but at a thinner buffer. It's not right or wrong. It just personal preference and how experienced you are.
Ask people at a local dive store who uses a few different brands before you decide. Good dive stores will give you a straight answer on what works and what isn't marketing. The better Cairns dive stores put out gear reviews and comparisons on their sites too