Perjury:
The general lack of candor was part of it yes. There were the deflections, such as when he declared that parties *only* happened on weekends, and the calendar showed him as being away/busy/out of town every weekend of the summer, hoping to misdirect from the July 1 date (a Thursday) in which he is noted as having a get-together with 3 of the very people named in Ford's account. When asked about this date by the Republicans' chosen prosecutor, he waffled and played for time until the Republicans could call a Recess, at which point the prosecutor was no longer permitted to ask questions.
There are the rehearsed non-answers to certain particular questions. For example any time a question was asked about drinking, his response is the now infamous "I liked beer, I drank beer, I still like beer", any question about partying or drunkenness was met with the nonanswer of "I went to Yale" or "I worked my butt off" or "I was top of my class". Any question asking him whether he thought an FBI investigation would be appropriate was met with the nonanswer of "I will follow through with whatever the committee deems necessary" or "I wanted a hearing from DAY ONE". The most telling moment of the hearing was when Sen. Blumenthal pushed him into a corner about this line of questioning, such that Kavanaugh at one point fell silent for 20 seconds, refusing to say ANYTHING, until Blumenthal noted this, at which point he went back to his "I will follow through with whatever the committee deems necessary".
The big ones, though are the obvious and outright lies. The first being whether he ever got excessively drunk or blackout drunk, which he has adamantly denied, although a) we have him admitting *in email* that he got blackout drunk as recently as 2001, and b) his friends from Yale and high school are now coming forward in droves to dispute his self-characterization as a non-drunkard.
The second major one is his answers to epithets given to him in his high school yearbook, and definitions of "what they mean". For example, "King of the Beach Week Ralph Club" was, according to him, a reference to the fact that he has a weak stomach, and not that he drank to such excess that he vomited. Or that he was listed as a "Renate alumnus", referencing a girl from a neighboring high school, which Kavanaugh claims was a sign of friendship and a token of Kavanaugh's and his friend's admiration for her, despite a) Renate not knowing about this excerpt from the yearbook until a week ago, and b) being horrified and disgusted upon hearing about it and fervently denying anything the appellation might imply.
Kavanaugh claimed that the "Devil's Triangle", a crass and obvious reference to a three-way involving two men and one woman (you know, what he and Judge allegedly attempted with Ford) was in fact a drinking game, although he couldn't actually explain the rules when asked to do so directly. He also claimed that "boofing", generally understood to refer to the act of ingesting alcohol through the anus, was a reference to flatulence. The lies in these instances were so patently obvious that someone from inside the Capitol building was scrambling to amend the respective wikipedia pages to include his erroneous definitions. There actually exists evidence of someone actively trying to cover Kavanaugh's ass as he blatantly and flippantly lied to the Senate Judiciary Committee.
Of course these declarations are absurd on the face of it, but recently many of Kavanaugh's classmates from Yale, most particularly his freshman roommate, have come forward to note that Kavanaugh knew very well what all of these words actually meant, and his trying to pass them off as something they weren't represented outright lies on his part.