Thanks.
It's a strange (and confused) behavior.
In[1]:= t = 7
Out[1]= 7
In[2]:= Table[Evaluate[t + 1], {t, 1, 10}]
Out[2]= {8, 8, 8, 8, 8, 8, 8, 8, 8, 8}
In[3]:= t
Out[3]= 7
In[4]:= Table[t + 1, {t, 1, 10}]
Out[4]= {2, 3, 4, 5, 6, 7, 8, 9, 10, 11}
In[5]:= t
Out[5]= 7