Как рассчитать размер стола?

Seating comfortably accommodates 8 to 10 people.

If chairs with wide seats or armrests are used, the table can only seat up to 8 people.

For "cabaret-style" seating, 6 to 7 people can be accommodated.

In cramped spaces, the table can fit 11 to 12 people if narrow chairs without armrests (such as "Chiavari-Bram" or "Hampson") are used and the table is not set with charger plates.

For a table with a diameter of 150 cm, comfortable seating: 6-8 people;
with wide chairs/with chairs with armrests: 6-7 people;
"cabaret": 4-5 people;
"in tight space": 10 people (narrow chairs, no armrests, no charger plate).

The general rule for rectangular tables is to place guests on both sides, calculating the minimum distance of 0.6 m per 1 guest. 
We do not recommend seating guests on the short side of the table, the exception is a kids chair
The minimum recommended width of the table, when seating guests on both sides – 100 cm. Charger plate and glasses, it is necessary to retreat 40-45 cm from each side, then there will be a small spot in the center for decor / candles / floristry.
Therefore, we recommend tables with a width of 120 cm.

The most common sizes of tables are 150 * 80 cm or 180* 80 cm (desks). Obviously, the width of 80 cm is not enough for comfortable accommodation of two guests opposite each other. Therefore, desks are most often used as modules, making up several tables into one large rectangular one.
Table size 240*120 cm ("Cabriole") comfortably accommodates 6-8 guests (3-4 on each side).