A 41-year-old man is in critical, but stable condition, after a stabbing Saturday on the Big Island.  The victim was stabbed at about 2:15 p.m. at 4-Mile Beach Park in Keaukaha.   Police responded to the call and found the victim with several stab wounds. He was transported to the hospital in critical, but stable condition. His alleged attacker, a 46-year-old Ocean View man was arrested shortly after the stabbing on suspicion of second-degree attempted murder.