LTspice table function
.step param n 0 5 1


Simulates the circuit for different values of n, starting at 0, stopping at 5, with steps 1. So, n is one of [0,1,2,3,4,5] 


  .param cc=0.01 ; delta


assign a value cc = 0.01, not sure what the delta is, probably just a coment, not a LTspice command.


  .param a1=table(n,0,0,1,1,2,0,3,0,4,0,5,0,6,0,7,0,8,0,9,0,10,0)


a1 gets a value based on the value of n, the table has the following structure,
table(index, pairs of key,value ). in your case n is the index, and the bold ones are the keys, followed by non bold values.
table(n,0,0,1,1,2,0,3,0,4,0,5,0,6,0,7,0,8,0,9,0,10,0)
Notice that, n is in [0,1,2,3,4,5], so many of those keys will never be reached/used


  .param R1=2k*(1+cc*a1)


Assign the value of R1 =  2k*(1+cc*a1), equal to, R1 =  2k*(1+0.01*a1), that for n=0 will be, R1 =  2k*(1+0.01*0). For n=2, R1 =  2k*(1+0.01*0), and so on.


  .meas Vout0 FIND V(out) when n=0


Gets a measurement called Vout0, that is V(out) when n=0.