We've always been able to get seated right away, but having said that the place fills up quite soon after.
Pretty much all the good eating places have folks waiting at some time or other. Most people want to eat out from around 6 pm in the evening we generally try 5:30 ish
Like you we have often had to wait for a table and sometimes up to an hour. Just the two of us.
Seems to me that eating out is a passion in the Philippines Regardless of the time of day places are always full.