tab2dat: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/unicon/bin/tab2dat - from package: unicon-imc2

You may install the required package with command apt-get install {package}
Error in other languages:
tab2dat: bevel nie gevind nie
tab2dat: comandă negăsită
tab2dat: comando não encontrado
tab2dat: commande introuvable
tab2dat: command not found
tab2dat: käsku ei ole
tab2dat: không tìm thấy lệnh
tab2dat: komanda nerasta
tab2dat: Kommando nicht gefunden.
tab2dat: kommandot finns inte
tab2dat: komut yok
tab2dat: nie znaleziono polecenia
tab2dat: níor aimsíodh an t-ordú
tab2dat: no se encontró la orden
tab2dat: no s'ha trobat l'ordre
tab2dat: opdracht niet gevonden
tab2dat: parancs nem található
tab2dat: perintah tidak ditemukan
tab2dat: príkaz nenájdený
tab2dat: příkaz nenalezen
tab2dat: команда не найдена
tab2dat: командата не е открита
tab2dat: 命令找不到
tab2dat: コマンドが見つかりません