The table is
\| \
x \ | \
\
y \ | \
| \
10 \ | \
\
1 \ | \
| \
11 \ | \
\
3 \ | \
| \
12 \ | \
\
5 \ | \
| \
13 \ | \
\
7 \ | \
From the table x increases by 1, y increases by 2.
\So, this is a linear function.
It represents a linear function.