One way ..
Assume your source data is
in Sheet1, in cols A to C, data from row2 down
In Sheet2
--------
Put in A2:
=IF(MOD(ROWS($A$1:A1)-1,2)=1,"",OFFSET(Sheet1!$A$2,MOD(ROWS($A$1:A1)-1,2)+IN
T((ROWS($A$1:A1)-1)/2),COLUMNS($A$1:A1)-1))
Copy A2 across to C2, fill down until zeros appear, signalling exhaustion of
data from Sheet1
The above will return what you want
(insert alternating blank rows in-between the data from Sheet1)
Do a copy and paste special as values elsewhere as desired