Always use the official consulate site for requirements, but your link appears to be accurate.
https://vientiane.thaiembassy.org/en/page/tourist-visa-2?menu=63bcd875e8b39d00fd0e7513
It takes 2 days to get the visa, so if you apply on Tuesday, you pick up your passport and visa on Thursday.
I applied last week in Vientiane for a Non-immigrant O visa, so the requirements are different, but they didn't deviate from the list.
They seemed most interested in the financial evidence from what I saw, so the more you bring the better.
You need a appointment to apply at Vientiane, there are no walk ups. The consulate is closed on July 20 for a Lao holiday and July 28 for a Thai holiday.
https://vientiane.thaiembassy.org/en/page/office-hours-and-holiday?menu=63bb90d69da54379d32269a3