O Allah, our Lord, Send down to us a Table [spread with food] from the Heaven to be for us a Festival for the First of us and the Last of us and a Sign from You.

A plea for a miraculous sign from Allah, emphasising the unity of the believers and their collective celebration. It also acknowledges Allah as the best provider.

اللَّهُمَّ رَبَّنَا أَنزِلْ عَلَيْنَا مَائِدَةً مِّنَ السَّمَاءِ تَكُونُ لَنَا عِيدًا لِّأَوَّلِنَا وَآخِرِنَا وَآيَةً مِّنكَ ۖ وَارْزُقْنَا وَأَنتَ خَيْرُ الرَّازِقِينَ

O Allah, our Lord, send down to us a table [spread with food] from the heaven to be for us a festival for the first of us and the last of us and a sign from You. And provide for us, and You are the best of providers.

Allāhumma Rabbanā anzil ʿalaynā māʾidatan mina as-samāʾi takūnu lanā ʿidan li-awwalinā wa ākhirinā wa āyatan minka. Warzuqnā wa anta khayrur-rāziqin.

Context

Recite this duʿā when seeking Allah's protection and assistance against oppression and injustice. To express unity among believers, acknowledge Allah's power to provide, and celebrate His blessings.
This dua is mentioned directly in the Quran in the context of the disciples of ʿĪsā (Jesus) asking him to request a table spread from Allah.

Benefits

During times of collective gatherings or when seeking a sign from Allah.

Source