What tabs? You mean the ones for each horoscope / module?
I once had a call from a woman who complained she could not calculate horoscopes anymore and got some error, when doing teamviewer it turned out she had reached the max of tabs i had set somewhere, she had about 100 horoscopes loaded.

Later on i was able to remove that limit. Never tried it myself though.
Since this is posted in astrobasic you probably mean ab's tab(). There is no limit in my code.