Align first row in a table

Question

I try to align my first row in a table. Only the first row needs another alignment.

%-----TABLE-----%
\begin{table}[H]
    \begin{tcolorbox}
    [
        tabularx={|Y|Y|Y|Y|Y|Y|Y|Y|},
        title=Uitvoeringstijd Full Search Algoritme (in ms),
        Table1
    ]
        tE      & blocksize & search-window & omroepster & tennis & vaneigens & vliegtuig & werkman \\ 
        \hline
        \hline
        0,00\%  & 8x8       & +8           & 20235      & 46191  &           &           &         \\
        0,50\%  & 8x8       & +8           & 251        & 17048  &           &           &         \\
        1,00\%  & 8x8       & +8           & 138        & 10226  &           &           &         \\
        0,00\%  & 16x16     & +8           & 11155      &        &           &           &         \\
        0,50\%  & 16x16     & +8           & 128        &        &           &           &         \\
        1,00\%  & 16x16     & +8           & 82         &        &           &           &         \\
        0,00\%  & 32x32     & +8           & 7843       &        &           &           &         \\
        0,50\%  & 32x32     & +8           & 73         &        &           &           &         \\
        1,00\%  & 32x32     & +8           & 60         &        &           &           &         \\
        0,00\%  & 8x8       & +16          & 66340      &        &           &           &         \\
        0,50\%  & 8x8       & +16          & 459        &        &           &           &         \\
        1,00\%  & 8x8       & +16          & 127        &        &           &           &         \\
        0,00\%  & 16x16     & +16          & 46148      &        &           &           &         \\
        0,50\%  & 16x16     & +16          & 158        &        &           &           &         \\
        1,00\%  & 16x16     & +16          & 81         &        &           &           &         \\
        0,00\%  & 32x32     & +16          & 32705      &        &           &           &         \\
        0,50\%  & 32x32     & +16          & 61         &        &           &           &         \\
        1,00\%  & 32x32     & +16          & 57         &        &           &           &         \\
        0,00\%  & 8x8       & +32          & 285377     &        &           &           &         \\
        0,50\%  & 8x8       & +32          & 1671       &        &           &           &         \\
        1,00\%  & 8x8       & +32          & 218        &        &           &           &         \\
        0,00\%  & 16x16     & +32          & 175305     &        &           &           &         \\
        0,50\%  & 16x16     & +32          & 255        &        &           &           &         \\
        1,00\%  & 16x16     & +32          & 85         &        &           &           &         \\
        0,00\%  & 32x32     & +32          & 136241     &        &           &           &         \\
        0,50\%  & 32x32     & +32          & 74         &        &           &           &         \\
        1,00\%  & 32x32     & +32          & 68         &        &           &           &        
    \end{tcolorbox}
    \caption[Tabel Cerlce]{Tabel Cercle}
    \label{tab: Tabel Cercle Brugge}
\end{table}

Answer 1

Since you didn't provide complete MWE I was faced with ungratefull task to make own. Since from your question is not clear, how to be formated first row, I decided to format table according to my taste:

(in table I consider only few first rows).

\documentclass{article}
    \usepackage{tabularx}
\newcolumntype{Y}{>{\centering\arraybackslash}X}
    \usepackage[dvipsnames,table]{xcolor}
    \usepackage[many]{tcolorbox}
    \usepackage{siunitx}
    \usepackage{stackengine}

    \usepackage[margin=25mm,showframe]{geometry}

    \begin{document}
\begin{table}[htb]
\sisetup{table-format = 6.2}
\tcbset{enhanced,
        fonttitle=\bfseries\large,fontupper=\normalsize\sffamily,
        colback=yellow!10!white,colframe=red!50!black,colbacktitle=orange!30!white,
        coltitle=black,center title}
    \begin{tcolorbox}
    [
        tabularx={|*{3}{Y|}*{6}{S|}},
        title={Uitvoeringstijd Full Search Algoritme (in ms), Table1}
    ]
tE      &   blocksize 
                &   \stackon{window}{search-}
                        &   {omroepster} 
                                &   {tennis} 
                                        & {vaneigens}
                                                &   {vliegtuig}
                                                        &   {werkman}   \\
        \hline\hline
0,00\%  & 8x8   & +8    & 20235 & 46191 &       &       &               \\
0,50\%  & 8x8   & +8    & 251   & 17048 &       &       &               \\
1,00\%  & 8x8   & +8    & 138   & 10226 &       &       &               \\
0,00\%  & 16x16 & +8    & 11155 &       &       &       &               \\
0,50\%  & 16x16 & +8    & 128   &       &       &       &               \\
1,00\%  & 16x16 & +8    & 82    &       &       &       &               \\
0,00\%  & 32x32 & +8    & 7843  &       &       &       &               \\
    \end{tcolorbox}
    \caption[Tabel Cerlce]{Tabel Cercle}
    \label{tab: Tabel Cercle Brugge}
\end{table}
    \end{document}

In formatting of table I use packages siunuitx (better alignment of numbers in table), stackengine (for two line head of third column). Column heads are still centered (I assume, that was task `` type for columns, all table remind me to example given in manual for tcolorbox), however, I may be wrong.

With package geometry with option showframe I set-up page and look how table fit in page. See, if so formatted table looks nice/usable to you.