Well firstly if you want size you're doing too much. Cut the abz day for starters thats stupid, you wouldnt do a bi's day or a calves day would you? take an extra rest day in the middle of your week. All growth is done resting, not lifting. Make sure your diet is good too, you dont sound like a chubber so make sure your getting lots of protein. Look at a meal and if it doesnt have at least 30g of protein in it eat something else!
Next, more reps less sets. Your bordering on a strength training program with 5x6. Personally for size i would adopt a 4x7+3 routine where you do the 7 reps then alternate slow eccentric movments with fast explosive reps. So for example, on the bench press you would lift 7 reps normally at a steady pace and with good form. Then for reps 7-10 you would rep as fast as humanly possible (even if this is not 'fast' in reality you must be
trying to press super fast). Then on set 2 complete another seven normal reps, but this time for reps 7-10 lower the bar super slowly to your chest count at least 5 seconds down with at least 3 breaths, press up quickly. Follow this pattern for all sets.
This is just one way of tailoring for size, the key to size is fibre activation (musle used) the best way to activate the most fibres in a workout is to use fast and slow tempos and correct volume, volume being total reps multiplied by sets multiplied by weight.
My last note is to cut down the exercises, as a relative beginner isolated work is pointless. Back and biceps should consist of deadlifts/chins/rows and pulldowns ONLY your biceps will grow just fine (mine are 18" and i gave up normal curls long ago!). Not sure what pulldowns are in chest and tri's day? Maybe tricep press downs? Either way dont do both those and skullcrushers in the same session. Move flies to the end of the session and only complete them if you feel your chest hasnt been hit hard enough, alternativley swap them in instead of bench press
o shock horror) now and again and do a close grip bench press.
Rest looks good but jesus i just looked again at back and biceps day and you HAVE to change that! 3 isolated bicep movments? Rookie mistake and counterproductive. You want big biceps get a big bent over row, big deadlift and big lat pull/chin+weight, doing 90 goddam curls in a session will get you nowhere!