Royals looked to be on course for a second successive Premier League win after Sean Morrison headed them in front in the first half at DW Stadium.
But even with a helping hand from Wigan goalkeeper Ali Al-Habsi, who dropped a routine catch into his own net with his side leading 2-1, the visitors failed to hold on for a point.
They were twice punished for giving Jordi Gomez too much space in front of goal and then conceded a third in injury time when the Spaniard completed his hat-trick while Royals were pushing for a winner themselves.
A furious Tabb lamented: "It's a bit of a joke. How many times have we taken the lead this season, and we've won once?
"Something has to change. We are not getting battered every week, we are taking the lead and getting in winning positions and not seeing it out.
"As players we have to be on the same wavelength and we are obviously not, we are either too deep or too high - that's what it feels like on the pitch. Instead of controlling the game at 1-0 we are giving away too many chances."
Royals were due to travel to fellow strugglers Aston Villa last night (Tuesday, 8pm ko)) then host Manchester United at Madejski Stadium on Saturday (5.30pm ko).
After that they face three away games in their next four at Southampton, Sunderland and Manchester City, with a home clash with Arsenal in between.
Tabb acknowledges that if Reading are to turn their fortunes around they must close the opposition down better and prevent as many shots on their goal.
"If you look at the stats, teams are having on average 16 or 17 shots a game and they are going to score goals," he said. "You can't allow 18 shots and expect your keeper to be man of the match each week, something has to change.
"We have shown we are capable of winning games, we keep taking the lead and have to turn these leads into wins.
"It's so disheartening when you don't take your chances, if you don't win at least take a point."
Tabb was at the heart of a potentially game-changing decision on Saturday when he appeared to be clearly upended in the box.
Referee Howard Webb waved away the Reading appeals, much to the frustration of the visitors and Tabb himself.
"It's a penalty, he hasn't got the ball and I have a bruise on the side of my foot, if it wasn't a penalty it should have been a yellow for a dive," he revealed.
"But even if we had scored they would have had more chances because we are giving them away."