The convert/table function converts a list or an array to a table. The table index is assumed to be entries with indices 1, 2, ...

$\mathrm{convert}\left(\left[\left[1\,2\right]\,\left[3\,4\right]\right]\,\mathrm{table}\right)$

$table\left(\left[\left(2\,2\right)=4\,\left(2\,1\right)=3\,\left(1\,2\right)=2\,\left(1\,1\right)=1\right]\right)$

$\mathrm{convert}\left(\mathrm{linalg}\left[\mathrm{vector}\right]\left(4\,\left[1\,x\,x^2\,x^3\right]\right)\,\mathrm{table}\right)$

$table\left(\left[1=1\,2=x\,3=x^2\,4=x^3\right]\right)$

$A≔\mathrm{linalg}\left[\mathrm{randmatrix}\right]\left(3\,3\,\mathrm{symmetric}\right)\:$

$\mathrm{convert}\left(A\,\mathrm{table}\right)$

$table\left(\mathrm{symmetric}\,\left[\left(3\,3\right)=\mathrm{-56}\,\left(2\,2\right)=\mathrm{-55}\,\left(1\,3\right)=\mathrm{-94}\,\left(2\,3\right)=87\,\left(1\,2\right)=22\,\left(1\,1\right)=\mathrm{-7}\right]\right)$