The 4 times table lists the multiples of 4: 4 × 1 = 4, 4 × 2 = 8, … 4 × 12 = 48. "4x" usually refers to this multiplication table.
"4x" can mean 4 times a variable, but most people searching it want the 4 times table: 4 × 1 = 4, 4 × 2 = 8, … 4 × 12 = 48.
Learn the multiples of 4 from 4 × 1 = 4 up to 4 × 12 = 48. Count up by 4 each time, or drill yourself with the table above.