Learn Russian: Обед был очень вкусный.

In Russian, past tense verbs change their ending to match the gender of the subject. Because обед (lunch) ends in a consonant, it is a masculine noun. Therefore, it takes the masculine past tense form был.

I learned that Russian skips the verb 'to be' in the present tense. Do we have to use it in the past tense?

Yes! In the present tense, you would just say Обед очень вкусный (Lunch [is] very tasty). But in the past tense, you must use a past tense form of the verb to be (был, была, было, or были) to show that the event already happened.

Why does вкусный end in -ый?

Adjectives must match the gender of the noun they describe. Since обед is a masculine noun, the adjective takes the standard masculine ending -ый. If the subject were feminine, like пицца (pizza), you would use the feminine ending and say вкусная.