What does it mean to plot a PAM signal over a number of symbols?
$10$ symbols means that you choose $N=10$, i.e., you plot realizations of

$$u_c(t)=\sum_{n=0}^{9}b_c[n]p(t-n)$$

and

$$u_s(t)=\sum_{n=0}^{9}b_s[n]p(t-n)$$

in the range $t\in[0,10]$.