Numbers file with unorganized data

Here is one way

Formula in cell B1 =INDEX($A,(ROW()−1)×3+COLUMN()−1)

Fill right to column D

Fill down 500 rows

The table has to be as shown in the screenshot for that exact formula to work. No header row, the data starts in cell A1. I could have simplified the math in the formula but it makes more sense as written. The zeros in the table are because I only had two sets of name/addr/tel. If I had filled the formula down to only two rows there would have been no zeros.

Fill right from B1:

1. Select cell B1 (one click)
2. Hover the cursor on the right edge of the cell and a little yellow dot will appear
3. Grab that dot and drag it to the right

Fill down with B1-D1

1. Select the range B1-D1
2. Hover the cursor over the bottom edge of the selection box and a yellow dot will appear
3. Grab that dot and drag down

However, you don't actually have to "fill down". For 500 rows it might be faster to select the range B1-D1, Copy, Select the columns B-D in their entirety, Paste.

That'll work, too.

The youtube video showed how to fill down in Excel. It is the same idea as described above except you grab the corner of the box, not the yellow dot (there is no yellow dot in Excel).

Select columns B-D in their entirety

Copy

Paste Formula Results (in the Edit menu)

Then you can delete A