I would encourage you to also refer to the
Malware Hub results of different AVs than solely relying on the AV Test Lab reports. Also, please do NOT base your decision on either of them alone.
Emsisoft is a light AV and one that you are probably looking for. Following the recommended alerts, you will be in a quite better position. The cloud anti-malware network they have, offers a very impressive protection against the undetected risky files of most types.
Another one is Kaspersky. Wait, it may be occasionally heavy on some systems, but some modifications in the "Performance" section helps.
Also, the 2018 version that will be out sometime soon (currently an RC) is found to be noticeably lighter than the earlier ones.
Your only concern if you go with KIS/KTS may be to effectively manage the "Application Control" module therein, that dynamically restricts applications based on their trust level calculated from different factors.
ESET has more signatures usually but malware/ransomware that manages to execute will get slipped through ESET.
I'm sure you meant "in quite some cases" and not
all get slipped through
I'll agree on this point. The engine is awesome, the Company's research work is well put. They were one of the very few who could in the early times block the Wannacry attack before DoublePulsar backdoor was installed.
However, it has a not-so-strong protection at default settings.
@uduoix with some hardening (if you think you can stretch to more advanced) you can fairly improvise it. There are a lot of guides available to fortify ESET HIPS and more.