A woman mixes with non-Mahrams and sits with them at one table to eat
It is not lawful for women to mix with men other than their Mahrams (spouses or permanently unmarriageable relatives) and eat with them from the same dishes, because this may cause temptation between them and consequently lead to sinning. So, women are required to be screened from non-Mahram men [in situations like this], eating alone or with other women. Allah (Glorified be He) says:
And tell the believing women to lower their gaze (from looking at forbidden things), and protect their private parts (from illegal sexual acts)
He (Exalted be He) also says: (Part No. 11; Page No. 318)
And when you ask (his wives) for anything you want, ask them from behind a screen: that is purer for your hearts and for their hearts.
Besides, the Prophet (peace be upon him) ordered that during congregational Salah (Prayer) the rows of women be behind those of men to avoid temptation. This is to be followed, with all the more reason, in cases other than Salah.