data = Table[{x, Exp[.2 + .3 x + .1 Sin[x] + RandomReal[{-.2, .2}]]},
                 {x, RandomReal[5, 100]}]; 
    nlm = NonlinearModelFit[data, Exp[a + b Sin[x] + c Cos[x]], {a, b, c}, x];
    pt = nlm["ParameterTable"];

You can also use `Part` as follows to access the row labels, column labels and the content of `pt`: 
    
    rowlabels = Sequence[1, 1, 2 ;;, 1];
    collabels = Sequence[1, 1, 1, 2 ;;];
    content = Sequence[1, 1, 2 ;;, 2 ;;];

    pt[[rowlabels]]
    (* {a, b, c} *)

    pt[[collabels]]
    (* {"Estimate", "Standard Error", "t-Statistic", "P-Value"} *)
    
    pt[[content]]
    (* {{1.00159, 0.0252967, 39.5938, 1.10726*10^-61},
        {-0.375734, 0.0304626, -12.3343, 1.3907*10^-21},
        {-0.157534, 0.0357183, -4.41046, 0.0000267067}} *)

    pt[[content]] == nlm["ParameterTableEntries"]
    (* True *)

    Row[Labeled[#, #2, Top] & @@@ {{pt,"ParameterTable\n"},
        {MapAt[Style[2 #, Red, 20] &, pt, {{1, 1, 2, 4}}], 
         "ParameterTable\nwith part {1,1,2,4} modified"}}, Spacer[10]]
![enter image description here][1]


  [1]: https://i.sstatic.net/dlFbc.png