HNS: it seems that u have a good knowledge in Arabic language as US national, and i appreciate it :)
there is a simple test which can be performed on any Arabic word ending with the sound "a" to know what is the suitable letter to use for it's end (alef maqsora or ta marbota): try to connect any pronoun to the word and see how the spelling will be,

- if it became "e", use alef maqsora (e.g. Ela => elaehe)
- if it became "t", use ta marbota (e.g. tawela => tawelatoho)

PS. the translation of the words used in the examples are as follows
Ela = To
Elaehe = to him
Tawela = Table
Tawelatoho = his table