What Does Enact Mean?
"Enact" means that a legislative body has finally passed a proposed law (a.k.a. a "bill") or proposed ordinance in a legislative capacity, causing it to become a law (a.k.a. an "act") or ordinance, rather than merely a proposal to pass a law or ordinance.
Your local council could enact an ordinance that was proposed to it to raise your rubbish collection fees, or parliament could enact a bill to reinstate the death penalty, or parliament could enact a bill to make an existing law gender neutral in its terminology.
In the U.S. when a regulation is brought into force to provide an executive branch department's interpretation or specification of something delegated to it in legislature an enactment, it would be customary to say that the regulation is "adopted" or "made" or "ordered" rather than "enacted".
But no one would be confused if you said that it was "enacted", in context, and British usage on this fine point might be different or evolving. The fact that your searches don't find "enacted" and "delegated legislation" in the same sentence, however, suggests that British usage hasn't evolved that far.
Minor Legislation
It does not seem logical that you should go thought the long righorous
law passing proceedure of passing multiple reading in the House of
commons and the house of lords, for just amendments, corrections and
minor improvements.
Logical or not, this is generally what is done. Indeed, the House of Lords largely justifies its existence by finding minor flaws in legislation passed by the House of Commons and sending it back to the House of Commons with amendments, corrections, and minor improvements to pass again.
But it usually isn't hard to get political support for these kinds of housekeeping amendments and nobody talks about them during Question Time, or makes long floor speeches about them in other floor debates.
The "Bill To Correct Typos and Grammatical Errors In The Tax Revision Bill of 2020" is offered up for consideration on the merits when its turn comes up, and in the absence of objection, it is adopted by unanimous consent, and boom, the Tax Revision Bill of 2020 isn't ugly and doesn't look like it was written by someone who skipped primary school anymore. This makes everybody in parliament look better.
The logic of this is an "equal dignities" idea. It should be as hard to change something enacted by parliament as it was to enact it in the first place. Unilateral executive branch officials shouldn't be able to override a decision voted upon by the entire House of Commons and the House of Lords by himself or herself.
Delegated Legislation Distinguished
Delegated legislation is (mostly, at least) what we in the U.S. would call regulatory authority.
Delegated legislation is not delegated because it is unimportant. It is delegated because MPs lack the capacity to articulate what it should say as well as executive branch officials.
A typical example would be in the environmental protection area. MPs know that pollution that is dangerous to people is bad, but they delegate the authority to the agency to decide what that translates to in terms of parts per billion kilojoules of energy produced of lead or particulate matter or CO2. These amounts are determined by agency scientists helping the minsters and their underlings in the agency determine the right amount based upon lengthy reports that most MPs wouldn't understand because they did PolySci instead of chemistry in college.
A radically different example that gets across the same idea would be that the parliament might delegate to the Defense Minister responsibility for establishing terms of engagement for British soldiers stationed in Afghanistan (i.e. rules for when they're allowed to shoot people), because the Minster's up to date knowledge of the situation and familiarity with military protocols, further informed by advice from the Ministry's generals and admirals, would allow the Minister to provide a rule that is more appropriate to the situation, that is more understandable from a soldier's perspective, than the House of Commons made up mostly of people who haven't served in the military and aren't familiar with what is going on in Afghanistan lately, would.